No-one had the slightest inkling that the 6ft 4in Dane was probably christened Rasmus Kirkegaard Kristiansen - and was a suspected murderer and identity thief.

Kristiansen had previously been known by ten other names and had lived for short periods in a number of ex-pat communities.

He's still at large, and his Interpol file reads "arrest on sight".

Stolen passports are extremely valuable to criminals

Theft of identity, however, is rarely so sinister or extreme, but has become prevalent in the USA.

Trans Union, one of America's major credit reporting agencies, says it received more than half a million requests for help from people affected by fraud last year - up from just over 35,000 in 1992.

The company receives about 1,400 calls a day from identity fraud victims.

In the United States, the term identity theft is domestic fare, and was last year heralded by the USA's Good Housekeeping as the "fastest growing crime of the decade".

It covers everything from theft and fraudulent use of passports, driving licences and other personal documentation, to lifting data from the Internet, such as credit card numbers, and details of e-mail accounts and their holders.

The UK's National Criminal Investigation Service is currently investigating how the personal details of a Birmingham teenager were stolen and used by an American drug smuggler.

Shabiya Davidson was contacted by British police after the villain was jailed this summer in the USA. He had given Mr Davidson's date of birth, and told customs officers he was from England's second city.

Other cases in the UK have involved the fraudulent use of someone else's details to claim benefits and local education authority grants.

The NCIS is calling on the FBI's expertise in the field of identity theft to prepare for its advent in the UK.

Shopping online - no-one needs to see your signature, or who you are

A spokeswoman told reporters: "This is a growing problem, especially in the drugs trade.

"Stolen passports, for example, are a valuable commodity in the criminal world.

"These days you can also store a lot of information on a disk and get details from the Internet, despite data protection checks."

Internet users can - unwittingly - leave a trail of personal information behind them.

Hackers can access information stored in cookies on a user's using habits - or provided in the registration process for various Internet services.

But the bastions of e-commerce are staunch in the defence of their sales medium, saying customers have nothing to fear from secure sites.

Julia Catton, spokeswoman for online bookshop amazon.co.uk, said that providing credit card details to them online is in fact safer than doing it over the phone.

She said: "We have a totally secure site, so that when people enter their credit card numbers, they can be certain that they are not seen by another person.

"Like many other interactive retailers, we use SSL encryption. The user's banking details are not viewed by anyone other than themselves and their bank.

"They go straight down a line to our server in Seattle and then directly to the banks. It is much more dangerous to give credit card details over the phone - or indeed to hand your card over at a restaurant, but everyone does that without thinking.

"We have 10 million customers worldwide and we have never once had a complaint of this nature."

She said credit card fraud online was much more likely to happen after a card had been physically stolen.

Credit card fraud is nothing new - but the advent of e-commerce means that huge debts can be run up on a stolen card, leaving little to identify the fraudulent user.

In North America especially, postal remailing services allow goods to be sent to "anonymous" addresses, from where they are forwarded to account holder's real postal address.

A typical rider on a remailing service reads: "We do not act as your agent or act legally for you. We merely provide a service. Since we do not open or in any way check letter or packages, you warrant to us that by using our service, you are not mailing anything illegal or dangerous or in violation of postal or other laws (such as explosives, extortion letters, threats, child pornography etc).

Credit card theft takes on a whole new dimension on the Internet

"You will hold us harmless for any losses for any such action."

For many people, the first they know that their identity being used to line the pockets of others is when the credit card bills start to roll in.

Most credit card companies will not make victims of fraud pay up - but the process of cancelling cards and just as importantly, straightening credit records, can be time-consuming and stressful.

But identity theft is not merely a modern nuisance - its victims can be left traumatised.

A young English teacher, whose identity was fraudulently used to obtain a mortgage in Texas, told USA Today: "It's just horrible. I feel so violated knowing that someone knows all my information."

The advice from credit companies and Internet service providers is to always use secure sites, and to make sure that credit cards are kept safe. Never carry spare cards.

And always destroy any receipts or statements with details on them - criminals do not need to have the actual card to use the account in cyberspace.