The number of reported UK identity thefts continues to rise, according to new data released by credit-checking agency Experian today - and identity thieves are showing more determination in picking out victims.

Some 2,124 people contacted the agency's helpline for victims of identity theft in the second half of 2006, a 69 percent increase on the same period in 2005.

Experian said about 45 percent of those victims were alterted to a problem by a financial services company that noticed unusual activity, while 41 percent found out through their credit report. The rest found out either after a refusal of credit, a theft or through notices they were being awarded credit they had not personally requested.

Experian said ID fraud has evolved from small-time criminals digging in garbage bins to sophisticated operations that target security weaknesses in web applications to collect information on victims, among other means. The personal information is then used to apply for loans and buy items.

Criminals are increasingly using a person's current address when applying for credit rather than a previous one, which increases the chances of a successful application, said Gary Wood, managing director of Experian's fraud prevention business.

But it is also bolder, requiring the thief to, for example, intercept a credit card before it reaches the person's letterbox. Often, that's accomplished by temporarily redirecting the mail to another address, Wood said.

Unsurprisingly, wealthy neighborhoods are particularly popular with ID thieves. Residents there are also the slowest to notice fraud, Wood said.

Residents of exclusive neighborhoods around Victoria Street in London's Westminster district were three-and-a-half times more likely to be targeted by ID theft than the UK average, Experian said. Overall, Londoners were two-and-a-half times more likely to be victimised.