Once upon a time, a Scouser in a shellsuit with the head of a bullet on the neck of an ox turned up at the Squires Gate helipad in Blackpool and went for a flying lesson in a helicopter. He paid £750 in cash. The notes were crisp and new. The chopper flew up and away over the Irish Sea, leaving the effluent plume from the Mersey and the metal prick of the Blackpool Tower far below. The chopper flew north over the grey, scudding sea to the peninsula of Barrow-on-Furnace where they turn out nuclear submarines for the Royal Navy. The Scouser pointed to a big square of grass down below, the grounds of the non-league Barrow Athletic Football Club, and said: `I own that.' Some boast. But it turns out that he wasn't short of a bob or a hundred million pounds. The scally's name was Curtis Warren, his nickname Cocky Watchman, Scouse slang for a dodgy caretaker, and he was, some say, the Cali cartel's agent for northern Europe. Her Majesty's Customs and Excise had a different name for him: Target One.

He's banged up now, serving a 12-year-stretch in Vught prison in the Netherlands, a former Nazi concentration camp, for importing enough cocaine into Europe to keep the London advertising industry happy until the year 2010. Meanwhile, British Customs officers and policemen, working in tandem for a Dutch judge, are beginning to unpick a fraction of Cocky's missing millions. Forget Kenneth Noye. He was just a fence, albeit for the Brinks Matt gold bullion robbers, and one with a nasty temper. Forget the Krays. They were just pathetic minnows. It is nigh on certain that Cocky is the richest criminal in British history.

I remember vividly the first time I ever heard the name Curtis Warren. Veronica Guerin, the brilliant Irish journalist had been shot dead in Dublin in the summer of 1996, for going after the heroin barons who were making themselves rich while a generation of Irish kids were getting suckered on smack. Her mission had been simple: follow the money. The Observer sent me off to find out who, and why, and how. And what were the names of the British Mr Bigs?

In search of the British Mr Bigs, I had gone to a pub to meet a Customs investigator, the late Bill Newall, who at that time was working for the heroin target team. Bill had `called the knock' on many heavy-duty nasties, including a number of Turkish heroin traffickers ...I asked Bill about the Mr Bigs, the ones that always get away. He took a pull on his pint and said: `Then you've got to go to Liverpool. And ask them about Curtis Warren.'

Who?

`He's nothing much to look at. The usual big Scouse tough guy in a shellsuit. But this one is good. He doesn't drink, smoke or use drugs. He's got a photographic memory for telephone numbers, numbers of bank accounts and the like. We've been looking for where he keeps his stuff. On a computer? In notes? No way. He carries it all inside his head." --This text refers to the Hardcover edition.