Jeffrey Lee Parson, the American teenager charged with unleashing a varient of the prolific MS Blast internet worm, was released on bail following a hearing Friday in the US Federal Court.

Parson, an 18-year-old from Hopkins, Minnesota, was arrested Friday morning in connection with the release of a variant of the Blaster worm on 14 August following a joint investigation by the US Federal Bureau of Investigation and Secret Service, according to FBI spokesman Bill Murray.

Parson was released on a $25,000 personal recognisance bond and directed to appear before a magistrate judge in Seattle, Washington, on 17 September, according to Pat Sabin, deputy clerk at the court. Parson was not required to put up any money to be released but will need to keep court officers informed of his whereabouts, Sabin said.

In addition, Parson will have to wear an electronic monitoring device and be confined to his home except to attend school, receive medical treatments and make court appearances, she said. The court also barred Parson from the internet and forbade him to use computers or "connected devices" at his home or any other location.

All computers have been removed from Parson's home.