Brock Turner released after serving half his sentence

Stanford sex attacker Brock Turner (Supplied)
Stanford sex attacker Brock Turner (Supplied)

Brock Turner, the Stanford swimmer whose lenient sexual assault sentencing sparked international outcry, has been released - after serving only half of his six-month sentence.

The 21-year-old was found guilty of sexually assaulting an unconscious woman behind a rubbish skip at a party.

However, his sentence sparked global outrage and calls for the judge to be fired.

Turner has now been released early for good behaviour - a decision which has outraged rape survivors and activists.

"This kind of unfair and unreasonable and unjustifiable sentencing is not going to be tolerated any longer," says sexual assault survivor and Stanford student Jacqueline Lin.

Turner's victim, who remains unnamed, said in a statement at the time the Judge Aaron Persky sentenced Turner that it was a "soft time-out, a mockery of the seriousness of his assaults, an insult to me and all women".

"How fast Brock swims does not lessen the severity of what happened to me, and should not lessen the severity of his punishment," she said.

"The fact that Brock was an athlete at a private university should not be seen as an entitlement to leniency, but as an opportunity to send a message that sexual assault is against the law regardless of social class."

The judge has voluntarily removed himself from hearing criminal cases.

Turner must now register as a sex offender, and he's been banned from parks, schools and other places where children are expected to gather.