The man who is speaking is helping to investigate what happened to the pounds 26m stolen in November 1983 from warehouse unit 7 on an industrial estate next to Heathrow airport. The unit belonged to Brinks-Mat, the security company, and its vaults held 6,000 Mars-bar-sized gold bars on the morning three masked robbers burst in.
Brinks-Mat still ranks among Britain's biggest armed robberies. The police investigation and subsequent court proceedings have cost possibly pounds 5m more than the value of the gold stolen. It has prompted several of the most penetrating inquiries into corruption inside the British police. And it refuses to go away.
More than a decade later, not one gold bar has been recovered. Many of those suspected of having laundered the vast haul are at liberty. Some of those who were convicted are now free, and they seem to be living on comfortable pensions. Now there is every indication that those involved count among the most senior aristocrats of organised crime anywhere in the world.
Last month, lawyers acting for Lloyd's - which insured Brinks-Mat at the time of the robbery - issued what could be the final round of writs against those they believe masterminded the disposal of the gold, after years of legal actions. Scotland Yard still has a team exclusively investigating the robbery. But it is the Lloyd's investigation which seems to be making the most headway. New laundering networks have come to light. In all, with interest, they are looking for around pounds 60m. About pounds 3m is thought to have been recovered.
Tony White, the only one of the three men who stood trial in 1984 for planning the robbery to be acquitted, is the focus of Lloyd's attention. At the time he was unemployed, drawing benefit, living in a run-down council flat on the Bonany estate, just off the Old Kent Road in south-east London. Since then, writs claim, vast sums have passed through accounts with British clearing banks.
Tony White is a part of the south-east London gangland which has produced some of Britain's most notorious criminals. Brinks-Mat is still a thing of kudos in that fraternity, but it has never deserved the romance attached to the Great Train Robbery: it was a brutal, vicious break-in. Meticulously planned over a year, three men forced terrified guards to reveal the combination to the vaults by tearing open their trousers and pouring a solution of petrol over their underpants.
One of the guards quickly confessed to being the 'insider' and claimed that his accomplices were Mick McAvoy, Brian Robinson and Tony White. McAvoy and Robinson were sentenced in 1984 to 25 years each. Mr White was acquitted after he alleged that police had concocted his interrogations. He claimed that critical evidence had 'disappeared' by the time the defence wanted to see it in court. Mr White had allegedly told his interrogators: 'If I do my bird, the biggest problem ain't you people, it's what the animals on the outside will do to my family to get their hands on the gold, so do I give it up or keep it?'
After his acquittal, he started spending. By 1987, he had invested a total sum of around pounds 450,000 in south - east London property. He has not stopped spending ever since. He moved to Marbella on the Costa del Sol during the mid-Eighties and bought a neat little town house. Among his neighbours was Charlie Wilson, the Great Train Robber. Spain does not automatically extradite to the UK, and it is a favoured haunt of wanted British criminals. He sent his children to the exclusive Aloha college and cruised around in a midnight blue BMW convertible while his wife drove a white Range Rover.
Despite this obvious and sudden wealth, it seems that Mr White, like all the others allegedly involved, cannot live an ordinary, legal life. By the late Eighties he was suspected as a drug smuggler by the Spanish police and had excited the interest of the South East Regional Crime Squad in Britain. Irritated by increasingly obvious surveillance, he left Spain. He had been arrested for alleged involvement in a plot to kill two Spanish undercover policemen. In his house, gems worth more than pounds 00,000 were found, along with a similar amount of cash. He said he had acquired them legitimately.
He returned to Catford in south-east London and tried to open a chain of tapas bars and a night-club. Then, in 1991, customs found a ton of hash hidden in a cargo of frozen chips on a lorry at Dover. Mr White, describing himself as a 'self-employed car dealer', was charged, and eventually acquitted last year. Underworld wags now call him 'Snow White' because since Brinks he has never taken a fall.
Mr White has moved back to Spain, living now in the sprawling mass of anonymous holiday homes half-way between Marbella and Fuengirola. Last week he was said to be making one of his regular trips to Tangier. Somebody said that the burly East Ender considers himself above the law.
Customs will not say whether they are still pursuing him but the word is that he remains on their 'most wanted' list.
So what has happened to the rest of the Brinks-Mat mob? Many of those sent to prison are now out. Tony Black, the security guard who grassed on the others, was sentenced to six years but came out early. Somebody in south London said last week that there is a contract still out on his life.
But the man causing most upset is Kenneth Noye. Noye was sentenced in 1986 to 14 years for handling the bullion. He was acquitted of knifing an undercover policeman to death just beforehand. That killing, one suspects, has inspired the police to take a special interest in the urbane frontman. Noye was into everything: he was a Fleet Street printing apprentice, then became a property developer and haulage contractor, with a big mansion in Kent. It was a long way from his very ordinary origins in Bexleyheath, south-east London.
Recently, police started to suspect that he was involved with an American cocaine smuggler while still in prison. They set up surveillance while he was on day release. The operation, like so many others connected with Brinks-Mat and its aftermath, was so secret that only a handful of senior officers were aware of it. But Noye, predictably enough, found out. He was tipped off by another south London gangster who claims to have been told, in turn, by a police officer on attachment to the South East Regional Crime Squad. The result has been one of the biggest corruption investigations for a decade.
While police were investigating how another of the Brinks-Mat crew was disposing of his share of the gold, they encountered two rottweilers owned by the man's wife. Their names were Brinks and Mat. So much for remorse. And the south London underworld seems to grow stronger and more influential. 'They have won,' said one source, himself once friendly with several of those involved with Brinks-Mat. 'And they go on winning. They are strong because they have the money and there is always one policeman with an eye on a comfortable retirement.'
Additional reporting by Nigel Bowden on the Costa del Sol