The Tennessee college student charged with hacking the email account of US vice presidential candidate Sarah Palin, has pleaded not guilty to the charge and was released without bond, according to court documents.

David Kernell, 20, of Knoxville, Tennessee, was arraigned before a federal judge on Wednesday, a day after a grand jury indicted him on one count of accessing a computer without authorisation. Earlier in the day, Kernell turned himself in to the FBI, a Department of Justice (DOJ) spokeswoman said.

After Kernell pleaded not guilty, he was released on his own recognizance. However, the court imposed conditions on Kernell, a student at the University of Tennessee at Knoxville, before releasing him. A DOJ spokeswoman in Knoxville confirmed that they include a ban on owning a computer and a restriction on Kernell's use of the Internet to e-mail and his college coursework.

Kernell was also forbidden from having any contact with Gov. Palin or her family, and cannot travel outside eastern Tennessee without the approval of a probation officer.

Kernell's trial date has been set for 16 December, with a pre-trial conference scheduled for 2 December.

Kernell, the son of Mike Kernell, a long-time Democratic state representative from Memphis, allegedly broke into Alaska Gov. Palin's Yahoo Mail account three weeks ago by using the webmail service's password reset feature. After he accessed the "[email protected]" account, he took screenshots of several messages and posted them on a public board, the grand jury said.

According to the indictment, Kernell used the alias "rubico" when he bragged about the hack online, then later tried to cover his tracks by deleting and changing files on his laptop computer.

Amateur Internet detectives linked Kernell to the rubico username shortly after the attack was made public. Several days later, Gabriel Ramuglia, the webmaster of a proxy service used by rubico traced the hacker's IP address to an Illinois company that provides Internet service to the Knoxville apartment complex where Kernell lives. The FBI searched Kernell's apartment on 21 September.

Kernell has been accused of computer intrusion before, although last time he faced only an afternoon school detention. According to one of his former teachers, Kernell allegedly broke into a school server about eight years ago while studying at Eastern Hills Middle School in Harker Heights, Texas.

If convicted of the Palin hack however, Kernell faces up to five years in prison and a fine of $250,000 (£144,000).