Within hours of their meeting in a West End bar 18 months ago, Ronnie and Ekaterina – or Katya, as she prefers to be called – had embarked on a rather farcical affair during which she appeared to try to match him vodka for vodka.

In true rock’n’roll fashion, 62-year-old Ronnie left Jo, his wife of 23 years, and four adult children to roam the world with a woman who was barely out of her teens. Inevitably, it all ended in chaos last December when Ronnie was cautioned for assaulting Katya, 21, during a drunken brawl.

He called her a nasty little Russian whore while she memorably described him as an ‘evil goblin king’. She sold her story and posed for pictures in Hello! magazine and went on ‘Celebrity’ Big Brother. He feigned indifference, went into rehab (again) and found another young girlfriend.

And there the story might have ended had it not been for a bizarre twist last weekend – a photograph of Ronnie and Katya, both in rather extraordinary headgear, greeting each other warmly on the doorstep of her flat in North London, where he appeared to stay for several hours.

So is their affair back on? Had he just come to collect that Rolling Stones CD she’d borrowed? Or was this another publicity stunt?

According to Katya, it was none of the above.

‘I didn’t tip off the photographer, really I didn’t,’ she says. ‘A couple of taxi drivers might have tipped him off. Sometimes they follow me. I was surprised when I saw the pictures in the papers.’

They had, she says, simply wanted a civilised and sober final meeting and to remain friends.

Look who's rolled up: Katya greets Tonnie Wood at the door of her apartment last weekend

‘After I came out of Big Brother, we actually did speak to each other every other day,’ she reveals.

‘We had always agreed that we’d see each other again, but I didn’t think Ronnie was ready before. I thought he’d stare at me too lovingly. But he was in the area and I thought we might as well get it over and done with.’

Katya says she was pleasantly surprised by how he seemed. ‘Nothing physical happened,’ she insists. ‘We only hugged. I showed him around my flat. A couple of my friends were also there so it wasn’t that intimate.

‘He stopped drinking a month ago and seemed calmer. His eyes looked brighter and his skin seemed clearer. We ate tuna sashimi – a takeaway – drank water and laughed about how crazy our relationship had been.

‘He apologised for his behaviour for the first time. I forgave him and we hugged. I think he has realised the world doesn’t revolve around him.

‘He said it was going well with Ana [Brazilian polo coach Ana Araujo, 30, his new girlfriend] even though I still think she is too young for him. I don’t think he’s sexy any more but we’re both on the right path now.’

Ronnie, apparently, was equally understanding about her branding him an abusive bully. ‘All he said was, “Am I that bad?” He hasn’t judged me.

Katya with Ronnie during happier times last November

‘He said I came across well on Big Brother and that Jonas [the contestant she flirted with] seemed like a nice man. We agreed we would stay friends.’

Adopting the weary tone of an exasperated adolescent addressing her parents, Katya explains: ‘When you’re good friends with someone you can say anything about them and it doesn’t matter. I was only joking when I called him an evil goblin king. It was a bit of a game.’

That notion of game-playing slots neatly into the common assumption that Katya is simply a gold-digger who seduced a foolish drunk who, save for his £60million fortune, had little to offer a young girl. But the rest of Katya’s story, as she tells it today, does not.

She doesn’t, as many expect, speak with the thick Eastern European tones of a Bond seductress but with only the softest hint of her long-lost mother-tongue. She thinks of herself as British, having moved to this country with her family when she was just two.

By her own admission, she comes across as ‘weird, awkward’ and even ‘stand-offish’. She is not some polished man-eater; nor is she a bohemian free spirit with scant regard for convention.

Instead, she is the product of a broken home, cultural drift and her own desire to be noticed. Perhaps her tragedy, such as it is, is that she has yet to work out as what or by whom.

Katya, aged 11, playing with a pet hamster

Born in Karaganda, a remote town in Kazakhstan, Katya barely remembers the country of her birth.

She says: ‘Sometimes Mum would say that if we hadn’t left Kazakhstan we would be living on a potato farm. I can’t remember what life was like in Kazakhstan and I haven’t been back since, but I know my family were poor and it was very grey.’

Katya’s father Sergei, however, is far from grey. He is a colourful, romantic figure – a free spirit in stark contrast to her, perhaps understandably, worried and grounded mother.

He studied architecture before becoming an abstract artist. But, as Katya puts it, ‘no one buys art in Kazakhstan’.

So when she was two, he and her mother, Irina, a shop worker, left the country in search of a better life with Katya and older brother Pavel, now 28 and a graphic designer.

The family spent a year in Denmark before moving to London, and were granted British residency.

Irina worked as a cleaner while Sergei struggled to sell paintings. Katya recalls: ‘Dad was free-spirited and wanted to travel. He valued happiness over money, while Mum worked all hours to provide for us.

‘They would shout and argue all the time. I didn’t understand why Mum was so uptight. I shut myself off from her. I had much more in common with Dad. We went to art galleries, on long walks and even backpacking in Mexico.’

Katya speaks of these ‘adventures’ as though they were part of some bohemian idyll instead of episodes in a desperately disrupted childhood that ultimately led to rootless adolescence and a failed romance with a rock star.

Her parents separated when she was ten. Five years later, Sergei, now 47, fell in love with expat Hong Kong artist Tsz Man Chan and moved with her to the Orkney island of Papa Westray, where they opened a studio.

Katya’s mother, also 47, met her new boyfriend, Andrei, a construction manager with whom she now has a three-year-old daughter, Alisa. Katya says: ‘They were preoccupied with falling in love. Everyone was so busy that I had no discipline.

'I was hardly ever at home. I went to gigs and clubs with friends from school. I’d oversleep and only catch the last class of the day. I drank, mostly beer, and experimented with cocaine and cannabis. I lied to my parents about what I was doing, but I enjoyed the freedom.’

Katya dropped out of school half-way through her A-levels, abandoned dreams of going to university and instead moved into a North London flat with friends.

‘One of their fathers owned it so we didn’t pay rent,’ she says. ‘We’d paint and listen to music and I could happily live on £10 a week.’

So when, 18 months ago, Ronnie walked into the Churchill bar in London’s West End and told her he loved her, there was no judder of a moral compass to hold her back. Instead she spent a night with him in his hotel suite.

They stayed up until dawn, snorting cocaine. As Katya recalls it: ‘There was a spark between us from the start. I didn’t feel guilty [about Jo] because I thought his marriage was already over.’

Katya insists she believed Ronnie and wife Jo's marriage was over before they embarked on their affair

Katya insists she was never starstruck by Ronnie but, with characteristic contradiction, then admits to having guzzled the two pints or so of vodka they got through each day just to impress him.

‘I only drank two or three drinks a night before I met Ronnie,’ she insists. ‘I never got rolling drunk. But everything was hazy in the first few weeks we met.

‘I’ve stopped drinking so much now. I’m trying to stop smoking as well. Before I met Ronnie, I smoked five cigarettes a week. I went up to 30 a day. Now I’m down to 15 a day.’

Katya’s parents differed wildly in their reactions to her affair. ‘Mum was more worried than angry,’ she says. ‘Dad said he just wanted me to be happy.’

Days after they met, Ronnie introduced Katya to his 54-year-old wife. He took her to the family home in Kingston, Surrey: ‘He introduced me as a friend. But his daughter Leah still shouted at me.

'I burst into tears and then Jo made us all vodkas and I passed out on her lap. The family seemed a bit nuts to me, although I’ve got nothing against them.’

The following week, Ronnie took Katya to his nine-bedroom home in County Kildare, Ireland. They drank vodka and made love. He painted her nude and they watched horror films.

On their return to Britain, they rented a £10,000-a-month flat in North London where life, as Katya describes it, was a strange mixture of rock’n’roll and domesticity.

It was not, she says, all first-class flights, five-star hotels and designer gifts – though all of those featured.

Katya recently found fame again after appearing on Celebrity Big Brother

‘Ronnie would cook me fried mushrooms and tomatoes on wholemeal toast and bring me tea in bed,’ she recalls.

‘We watched wildlife programmes. I would cook boil-in-the-bag fish for dinner and make him espresso coffee. I’d lie on the sofa and Ronnie would trace the alphabet with his finger on my back. He sang while he did the dishes.’

And, prior to rehab, he drank vodka non-stop from midday. Ronnie’s limping journey from rehab to rehab is well documented.

Ultimately, Katya says, his relationship with drink overwhelmed their own: ‘I didn’t know if he’d be passed out when I got home. I was ashamed I didn’t have a job. Alcohol made me feel ill.’

Four months ago, in a desperate bid for attention, she slashed both arms with a pair of scissors. She ended up in hospital with 12 stitches. ‘Ronnie wouldn’t see me there because his management didn’t want the Press to find out,’ she says.

‘When I came out, the only thing he did was offer me a drink. That was his solution to everything.

‘My heart has been blackened by what happened. By the end, I was dead inside. I felt isolated. I lost all confidence and I’m still having counselling. I’m not a Russian whore.’

In fact, Katya never seems to have had an exit strategy to ensure her any lasting benefit when the relationship collapsed.

True, her apartment today is now somewhat nicer than the scruffy little London flat in which she was living when they met. And she is able, for the time being at least, to live off her reputed £200,000 earnings from Big Brother and Hello!

To say Katya is a contradiction is like suggesting Amy Winehouse is partial to the occasional shandy. She claims to be worldly, then admits that when she started work as a waitress at the escort bar where she and Ronnie met, she had no idea of the nature of the business.

She claims her relationship with him was based on genuine affection and has softened, today, into friendship. Yet she has rubbished her former lover in print and shows little empathy for his devastated family.

Ronnie might have kidded himself that he was bored with Jo, the ever-lovely, ever-understanding mother of his children. But they were a family and had been for more than two decades. Surely only the most hardened of home-wreckers could trample over that without a backward glance?

But there is no hint of regret from Katya, who sticks to her line that the marriage was dead by the time she came along and Jo came out of it well, kick-starting her ‘career’ on Strictly Come Dancing.

She ignores the fact that, while Jo has been mature and forgiven the ex-husband whose foibles she knows only too well, Ronnie’s children have been less understanding.

Last week, Ronnie and his daughter Leah had a quiet farewell dinner at a Chinese restaurant in Esher, Surrey.

Leah, 31, is said to be so upset at her father’s drinking and immaturity that she is moving to Australia with her husband and child for six months. Ronnie’s son Tyrone, 26, is said to have sided totally with his mother and feels his father is an embarrassment.

Still, Katya likes to believe that no real damage has been done. She claims to have done and seen more than most women twice her age, but doesn’t appear to have considered that she has confused instant gratification with experience and maturity.

All she will concede is that ‘Ronnie was too old for me’, echoing the much-voiced opinion of most.

Now dating Ana Araujo, Ronnie seems neither scarred nor transformed by his affair with Katya.

As for Katya, she claims: ‘I don’t care what people think. I can laugh it off. Life’s too short for regrets.

I realise now that money can’t buy happiness. But people who say I am a gold-digger are ignorant. I loved Ronnie for who he was, not for his fame or his money.’

Perhaps she genuinely believes that. But it is hard to escape the suspicion that Katya ‘loved’ Ronnie more because of who she is – a rather rootless young woman given few moral guidelines by the adults around her – than anything he had to offer.