Two men have been sentenced to a total of 10 years in prison for their roles in a wide range of online fraud activities, U.K. authorities said this week.

Douglas Harvard, a 24-year-old U.S. citizen, was arrested by the National Hi-Tech Crime Unit (NHTCU) in Leeds earlier this month during an investigation into a conspiracy by Eastern European crime syndicates.

Upon his arrest, police found documents, correspondence and equipment for creating false identities, as well as evidence that he was being assisted by a second man, British citizen Lee Elwood. Elwood, who is 25 and based in Glasgow, was arrested a few days later and charged with conspiracy to defraud after police found a large quantity of forged bank documents, credit card holograms, computers and other equipment, according to the NHTCU.

Both men were found guilty of conspiracy to defraud and conspiracy to launder money. Harvard was given six years in prison, while Elwood was given four.

The pair's extensive online fraud activities led authorities to warn about the growing rate of cybrcrime. Both men were heavily involved in Web sites that promoted and facilitated a range of criminal activities, according to the NHTCU.

The men stole at least £750,000 (AU$1.784 million) over a 10-month period and they may have banked as much as £6.5 million over two years, the NHTCU estimated.

Harvard and Elwood were moderators on the Cardplanet and Shadowcrew Web sites, which gave them the ability to monitor, approve and post articles to newsgroups. Once the suspects contacted each other over the Internet, they exchanged stolen information and counterfeit documents, authorities said.

Harvard admitted to receiving a large amount of credit card and password information from individuals in Russia, according to the NHTCU. He and Elwood used the information to buy goods and then had other people sell them at online auction sites and deliver the bulk of the proceeds back to them. After taking their cut, the men would send the remainder of the money back to their contacts in Russia, the NHTCU said.

The two also ran a U.K. syndicate which used identities and bank account information to retrieve cash from ATMs, police said.

Organized crime is always on the look-out for ways to make money and has now realized that the Internet affords them such opportunities, the NHTCU said in a statement.