They are mostly ordinary names at ordinary addresses. Mr X at 74 such-and-such Avenue, Mr Y at 46 so-and-so Drive (they are nearly all men). They live in average homes in suburban roads from Chichester to Aberdeen, from Tiverton to Newcastle upon Tyne.

Outwardly they probably lead respectable lives but behind their front doors, in the solitude of the rooms where they keep their computers, they pay to become voyeurs in a cyber-world of depravity.

This is the list, compiled by investigators at the US Postal Inspection Service, of British people who have paid to access websites displaying graphic images of child abuse and bestiality. There are more than 7,200 of them, but the document runs to 1,000 pages because the entries log details of different user names and the frequency of their visits.

Then, as you scan down the list, names begin to jump out: senior business executives, a television producer, a historian at a top university. A few names are clearly false — used merely for cover — but in most cases, including that of Pete Townshend, the guitarist with the Who who has admitted accessing a child pornography site for research purposes, the names, credit card details and addresses do match. Fictitious “user names” can be used, but paying requires a genuine credit card, which has led police to their true owners.

A famous newspaper columnist is named, along with a song writer for a legendary pop band and a member of another chart-topping 1980s cult pop group. A well known City PR man and a management guru appear, along with an official with the Church of England.

Personnel at military bases are also represented: people logged on to the paedophile sites from Mildenhall, Suffolk, Buchan, near Peterhead, Scotland, Strike Command in High Wycombe, Waddington in Lincolnshire and Leeming in North Yorkshire.

For weeks rumours have circulated that the names of two Labour ministers appear on the list; but, other than obviously false names, none does.

The suspects come from all areas and all sorts of professions — the law, publishing, the civil service and teaching, including two staff members at Millfield, the private school in Somerset, who were recently arrested (after which the school made it clear that the police inquiry had nothing to do with pupils). A large number of entries appear to be merchant bankers, City lawyers, high- flying accountants and company executives.

A geographical analysis of names with addresses suggests that two-thirds are based in London and the southeast. The stockbroker town of Guildford, with a population of 130,000, has 10 people thought to have accessed child porn websites. Reading has 30 suspects, Southampton 15, Milton Keynes 14 and Brighton and Hove 12. The area around Cambridge, with a population of just over 100,000, has 20 people appearing on the list, with several in the small town of St Neots.

All the suspects are said to have used their credit cards to pay a £21 monthly fee to Landslide Productions, the Texas firm that provided them with links to 300 pay-per-view child pornography websites.

With titles such as Cyber Lolita and Child Rape, the sites were so explicit that they shocked even the most seasoned detectives. An eight-year-old girl and her six-year-old brother, both from Manchester, are among the few youngsters so far identified. A Scotland Yard officer said they had been abused by their stepfather and photographed in sex acts.

The US inquiry began three years ago and investigators face a mountainous task in corroborating the details. Forces across Britain have spent seven months working through the names of those in their area. So far more than 1,200 have been arrested. Hundreds more will be questioned in the next few weeks, their homes and offices searched and their computers seized. Some users accessed the sites only once. But many on the list cannot argue that they did not know what they would be viewing: the records show that some accessed the internet service at least 50 times.

The investigation into the “master list” of 7,272 British suspects, drawn from an estimated 75,000 international subscribers, is known as Operation Ore. Detectives privately admit that in its early stages it was mismanaged and that a shortage of resources led to a huge logjam at police forensic science laboratories, where seized computers are examined.

“It was a shambles,” said one senior Scotland Yard detective. The National Criminal Intelligence Service initially focused on suspects who had most frequently accessed the site. Only later did senior officers realise that they needed to concentrate first on those who posed the greatest threat to children.