So where's Bacon's 'missing millions'?

Muriel Belcher wanted to take Bacon to one of Edwards's pubs and asked David to lay on some champagne which, of course, he was left trying to sell to his unimpressed punters because the mercurial Bacon didn't show up.

When John Edwards, who managed one of the pubs, was introduced to Bacon a few weeks later, he gave the artist "some stick". More used to being fawned over, Bacon was enchanted by this plucky, handsome young man. That he appeared to have a complete lack of education (Edwards, who was dyslexic, left school at 15 and could barely read or write) seemed to make him even more compelling.

"It was obvious he was taken with John," says David. "John didn't bow down to him - he wasn't intimidated by Bacon's money or influence. Later, when they became friends, John was always very truthful to him and they used to have the odd fight but John wasn't scared of him."

David says he shared this strong character with his brother. They would have needed it - John and David Edwards were both gay and it would not have been easy for them growing up in working-class Wapping. Bacon, on the other hand, was the son of a wealthy middle-class family.

The Edwards brothers' father worked at the docks, their mother worked in a delicatessen in Hackney and they had two older brothers and two sisters. "Both my older brother and my father were champion amateur boxers so it didn't go down too well to have two poofs in the family," says David. His father found this difficult to accept at first. But the brothers were successful publicans - "If we had been gay and poor, it would have been a problem. Fortunately, we both made good money and with that came respectability."

Although David refuses to say whether his younger brother had any relationships with women, his own love life was muddled. David got married at the age of 26. "I said 'I do' when I should have said 'I don't'," he remembers with a wry smile.

The marriage lasted just three months - it broke down because his wife found out he was having an affair with a woman who was six months pregnant. Then, shortly afterwards, he met his partner John Tanner, a keen horseman and interior designer, at a party "and I fell madly in love with him and decided that John was for me". They have been together for 30 years.

He says his son, now 30, has always accepted his father's relationship with Tanner. "I left his mother and I've been with the same person ever since. If I'd had different partners, it might not have been so easy."

David and his partner have lived together in their huge Grade II listed Georgian house in a Suffolk village since 1976 (though they recently decided to sell it and it is on the market for £1.5 million). He hosted parties there for his bohemian friends, including Bacon.

The artist would return the favour at his house in Withenhoe, near Colchester, but David recalls the supper at which Bacon had nothing to feed his guests apart from a piece of steak, an onion and a carrot - so he chopped them up, put everything in a pot with three bottles of vintage Chateau Petrus and made "soup".

Eventually David ploughed the money he had made from his pubs and clubs into an antiques business in Suffolk, but his brother remained in London. John, too, had made money from the business, but Bacon regularly gave him more (he even bought a flat in South Kensington for Edwards and his partner).

Bacon and John Edwards were inseparable. No matter how late Bacon had been up drinking or gambling the night before, he was always up at dawn to paint, usually with a hangover, and Edwards was the only person allowed to watch him work. He'd sit with him in his tiny, messy studio in Reese Mews, South Kensington. "We'd talk about everything," John Edwards said in 2002. "He was a beautiful man; you'd be hypnotised by him. He'd talk to you and you'd just want him to talk more."

"John and Francis would go out a couple of times a week," says David. "Usually to Charlie Chester's casino." There, Edwards would secretly pocket some of Bacon's chips to ensure that his gambling friend never went home with nothing.

"Their relationship was equal," says David. "Francis would always make sure John was comfortable. If he thought he was out of his depth in a social situation, he would make John look really important in front of everyone."

When Bacon died in 1992, Edwards was said to be "devastated". He moved to Florida with Philip Mordue, known as Phil the Till because he always seemed to have rolls of cash on him, then to Thailand, where he lived for six years before he was diagnosed with cancer.

He visited England for treatment and to see his family but always returned to Thailand, where he died. "They have a different approach to death - there's not the fear that we have here - and that's what appealed to him," says David. "He wanted to die there. The end came quickly. I was with John in Thailand the week before he died. He looked okay and that's why I flew back to England. I'd only been home for two days before I had to go back."

And the remains of Bacon's fortune? That is still shrouded in mystery.

The John Edwards Charitable Trust was set up after his death to further the study of Bacon's work but yesterday, Liz Beatty, the administrator said: "I am not prepared to talk about anything to do with the charity but what I will say is that John was a fantastic man."

So I turn to David Edwards. He looks at me and asks: "You want to know if he squandered it?"

I had rather hoped that John had blown prodigious sums of money on Cristal, which his late friend would surely have approved of. In his will, Edwards stipulated that £50,000 should be spent the "farewell" party that was held 10 days after his death, at the Harrington Club in Kensington. "We drank it dry," says David.

It is believed some of the money was spent turning Bacon's mews studio into the plush pied à terre it is today. John also bought his mother, Beattie, a cottage in Suffolk near a farmhouse he owned there (and there were luxurious apartments in New York, London and Pattaya in Thailand).

But David won't say exactly who got what ("John's will was private and that's the way he wanted it") except to say that "the people he loved were all looked after". This includes John's partner, Mordue.

Did John sell any of the paintings? "I don't know," says David. Does he have any of Bacon's paintings? There's a long pause and he gives me a steely look. "No comment," is all he will say.

His mother kept a Bacon triptych, thought to be worth £3million, in her old Hackney council flat (although David says it was a copy).

"John was very shrewd," says David. "And he was very generous. He knew he was going to die 18 months before he did. He used that time to do with his money what he thought best. He wasn't going to take it with him." Once again I feel that Francis Bacon would have approved.