A 25-year-old Japanese man has been arrested in Tokyo for allegedly sending 2.2 billion spam messages advertising gambling and dating services under the guise of a fake identity, according to Japanese media reports.

Police in Tokyo said on Friday that they had arrested Yuki Shiina after receiving a complaint from an ISP last year about the vast amounts of emails he was sending, Japan’s English speaking news service, Japan Today reported.

Police believe Shiina sent 2.2 billion spam emails since May 2006; bought 600,000 email addresses off the internet for US$927 and earned over US$18,540 through the spam campaign.

The 2.2 billion emails were sent as part of nine email campaigns, speculated reports.

Commenting on the arrest Paul Ducklin head of technology at Sophos APAC said: "While it doesn’t necessarily stop the unreconstructed spammers, it at least makes it clear to people who are toying with the idea of operating within the border of the law that this is not going to be tolerated by law enforcement,” Ducklin said.

Japanese law prohibits sending spam with fake sender information after the introduction of a law in 2002 and 2004.

"Spammers believe they can escape the long arm of the law by hiding on the internet, but increasingly the authorities are cracking down on this kind of Net abuse," said Graham Cluley, senior technology consultant for Sophos.

"No-one who hears about a single person believed to have sent 2.2 billion spam emails can be in any doubt as to the scale of the problem," he added.

According to Ducklin, over 90 percent of spam is sent through bots.

"That means there is an unholy alliance between spammers and people that actually have illegal access to other people’s computers and that can’t be tolerated," he said.