Los Angeles, Oct 1 (IANS): Former NFL star O.J. Simpson was freed on parole on Sunday after serving nine years in prison for a Las Vegas armed robbery, a Nevada prison official said.

"O.J. Simpson is out, he is a free man," CNN quoted Nevada Department of Corrections spokeswoman Brooke Keast as saying.

Simpson was picked up by a friend, according to Keast.

The Nevada Board of Parole Commissioners voted unanimously to grant Simpson's release in July.

Simpson, 70, served nine years of a 33-year sentence for kidnapping and armed robbery after a raid on memorabilia dealers in a Las Vegas Hotel room.

Simpson has maintained that he was trying to recover family mementos and memorabilia taken from him.

After he was granted parole, the Nevada Department of Corrections took extra measures to protect him, reports CNN.

Guards moved him to a single cell away from the rest of the prison population.

"The last thing we want is some prisoner trying to make a name for himself by attacking Simpson," Keast added.

The Nevada conviction came eight years after Simpson was acquitted by a California jury of the 1994 murders of his former wife Nicole Brown Simpson and her friend Ronald Goldman.

Simpson lost a civil judgment in 1997 for their wrongful deaths and was ordered to pay the victims' families $33.5 million.