THEY kissed passionately for the camera in an erotic music video – then Madonna fell in love with her co-star for real.

Now supermodel Amanda Cazalet has told for the first time how the music icon became so infatuated with her that she “stalked” her for two years — and sent her a series of yearning love letters.

In an exclusive interview with The Sun on Sunday Amanda, now 53, said: “Madonna became obsessed with me. What she did would now be classed as stalking and how she treated me would now be seen as inappropriate.

“At the time I wasn’t offended but, looking back, I realise I was taken advantage of by someone who, at the time, was my boss.”

Madonna, who turns 60 next month, was 32 when she spotted Amanda, 25, strutting the catwalk for fashion designer Jean-Paul Gaultier in Paris in 1990.

The English beauty was Gaultier’s muse, his model for all his illustrations, shows and campaigns. Her figure was even the inspiration for his torso-shaped perfume bottle.

Madonna had gone to the show to talent-spot models for her upcoming video for single Justify My Love.

Mum-of-two Amanda, who lives near St Albans, Herts, told us: “Jean-Paul and Madonna were friends so when she was looking for models she came to his show. I wasn’t a fan but I was flattered to be picked.”

The video was shot at the Hotel Royal Monceau, in central Paris.

Amanda recalled: “It was a strange job. I’d been modelling for six years by then but it was the first time I’d been on a set like that.

“Madonna hired the entire floor of the hotel, where we all stayed and the shoot took place there, too. I was paid just under £5,000 for the three days.”

The video included the singer walking down the hotel’s hallway, looking distressed and tired from work — then being seduced into having sex with a mysterious man and woman, played by Amanda.

She recalled: “I went into the room where it was being filmed and was told to start making out with her on a bed. Madonna and I were very close, our hands were all over each other.

“I wasn’t offended, back then I was bisexual and I was acting, being paid to do a job. I had no hang-ups about my sexuality.

“But we started to kiss and Madonna suddenly put her tongue in my mouth. I carried on, I was being professional and she was my boss.

“It was not part of the job description though, and I was put in a position where I couldn’t do anything about it.”

The video caused controversy worldwide for its depictions of sadomasochism and bisexuality and was banned from networks including MTV.

Meanwhile, Madonna, who had divorced first husband Sean Penn in 1989 after four years of marriage, was flaunting her own bisexuality.

She encouraged rumours that she was having an affair with bisexual actress Sandra Bernhard and was seen kissing Sandra’s lover, club owner Ingrid Casares, in her controversial 1992 book Sex.

Shortly after the Justify My Love video was released, she declared: “I think everybody has a bisexual nature. That’s my theory. I could be wrong.”

More recently, in 2003 she caused a stir by snogging both Britney Spears and Christina Aguilera on stage at the MTV VMA Awards.

Amanda first realised Madonna had fallen for her six months after the video shoot, when the model was back in Paris.

She said: “I went to Jean-Paul Gaultier’s office and there were a load of faxes from Madonna to me — love letters. Madonna said, ‘I find you attractive, I fantasise about kissing you again’. She said she wanted to meet me. And there was her own number and address on there.

“I was settled down in a relationship with a man but I was flattered. It was cool to have Madonna desperate for you.”

But she was not allowed to keep the faxes. Amanda explained: “He didn’t give them to me, just showed them to me. Even though they were my property I wasn’t allowed them.

“The next time I went over to see Jean-Paul a few months later there were more faxes. There were about six in total. I was surprised she was carrying on when I’d not responded.

“They were all the same, telling me she wanted to see me, telling me how she fancied me, how she wanted me to get in touch. I was never offered them to take away and I didn’t feel in a strong enough position to ask for them.”

Determined Madonna then arranged for a letter to be hand-delivered to the supermodel’s agency in London.

In the 1991 note — now up for auction and expected to sell for at least £16,000 — Madonna jokes about the difficulty she had in finding Amanda.

She writes: “Amanda, How are you? Where are you? Why don’t you call me . . . ? Getting in touch with you is like trying to seduce the Pope!”

It then begs her to get a modelling gig in the US so they can meet.

She then adds: “You have to send me pictures, lots of them. I think you are the most beautiful woman in the world. I’m dying to kiss you again. I fantasize about you all the time.

“I cannot explain my attraction — nevertheless it’s there. I’m attracted to very few women in this way.

I wish I could see you . . . please write . . . or call . . . or fax . . . ”

She lists her address, personal phone number and fax line, before signing off: “Love & kisses, M.”

Amanda did not respond, but Madonna was not daunted.

This time she contacted the London agency to invite Amanda to come to the cinema with their mutual friend Steven Meisel, the photographer who took the pictures for Madonna’s book Sex. Amanda, who now models part time and is writing her autobiography, said: “I was flattered. We met at her hotel, the beautiful large suite was full of models.

“Madonna made a beeline for me. I remember I was wearing a little black dress and she smiled when she saw me.

“She had arranged cars to the cinema and said I had to go with her and her driver.

“It was our first time alone together in the back of the car.

“She poured her heart out to me. There was no mention of the letter or faxes but she talked about her dad, her brother, losing her mother. She said how much she admired me for my modelling. She seemed lonely and needed someone to talk to, be with, be open with.

“We all crept into the cinema. She sat next to me and in the middle of the film put her hand on my leg and whispered softly, ‘I find you attractive, does that faze you?’

“I replied, ‘That doesn’t bother me at all’, to make it clear she wasn’t freaking me out, but left it at that. She finally took the message — I had no intention of pursuing things.”

That was the last time Amanda ever saw Madonna, who is now mum to Lourdes Leon, 21, son Rocco Ritchie, 17, and adopted David Banda and Mercy James, both 12, and five-year-old twins Estere and Stella Mwale.

She said: “I carried on modelling. I took Naomi Campbell under my wing when she was 14 in Paris and helped launch her career.

“Cindy Crawford and I were mates. I will always remember her excitement when Richard Gere first asked her for a date.

“There were some silly times — at a Paris show I was asked to drink from a bottle of vodka on the catwalk but got so drunk I crashed into a mirror.”

Amanda, who is currently single, also dated celebrities including the singer Seal — but faced the tougher sides of modelling, too.

She said: “There were models who ate tissues to stay thin because it filled them up.

"In Milan a photographer had me pinned up against a wall and kissed me.

“I rang my agency in tears and they said, ‘Oh he does that with all the girls’, as if it was OK.

As she fell out of love with the business she began turning down jobs, which left her short of money.

So in 2004 she sold Madonna’s handwritten letter to a collector for £4,000 in a private deal. Now that collector is re-selling it an online auction, to Amanda’s horror.

She said: “I never intended this to go into the public arena. I handled this with dignity and didn’t want to expose Madonna — even after the way she treated me.”