A 23-year-old Russian man, Oleg Y. Nikolaenko, who was accused of heading a world-wide spamming network, pleaded not guilty in a federal court in the US state of Wisconsin on Friday.

Mr Nikolaenko has been accused of running a global network of more than 500,000 infected computers, which are violations of a US anti-spam law. He has asked to be allowed a type of house arrest, subject to a trial.

"He is a citizen and resident of Russia and the government believes, if released, he would seek to return there and the government wouldn't be able to prosecute him," said the prosecutor Erica O'Neil.

Mr Nikolaenko's group is accused of running a botnet on infected computers to send billions of spammed email to internet users. Prosecutors alleged that the infected systems were capable of sending as many as 10 billion e-mails per day.

The group was at one point responsible for sending one out of three spam emails around the world. Mr Nikolaenko accused of violating the anti-spam law by sending false information in commercial emails.