Two cyclists who intervened in the Stanford sex attack have spoken out after the sentencing of campus rapist Brock Turner. Swedish students Carl-Fredrik Arndt and Peter Jonsson cycled past Turner as he was assaulting an unconscious woman outside a party on the university's Palo Alto campus on 18 January 2015 and challenged the attacker.

The two PhD students were praised by the victim, known as Emily Doe, in a powerful victim impact statement she read in court, which said: "Most importantly, thank you to the two men who saved me, who I have yet to meet.

"I sleep with two bicycles that I drew taped above my bed to remind myself there are heroes in this story. That we are looking out for one another. To have known all of these people, to have felt their protection and love, is something I will never forget."

The cyclists were key witnesses during the trial, at which they described seeing Turner on top of an unconscious woman and chasing him as he fled the scene, catching up with him and holding him until police arrived.

Following sentencing that prompted outrage due to its leniency, when Turner was handed six months in a county jail as opposed to the six years in prison requested by the prosecution, the students have spoken out about the attack.

Arndt told Swedish news outlet Expressen, in a statement translated by Buzzfeed, "We saw that she was not moving, while he was moving a lot.

After the students called out to Turner and he stood up, they realised the woman on the ground was unconscious.

Brock Turner
Brock Turner's January 2015 arrest mugshot Santa Clara County Sheriff's Office

"When he got up we saw that she still wasn't moving at all, so we walked up and asked something like 'what are you doing?'" Arndt continued.

In a comment on his Facebook page, Jonsson wrote: "Thanks to everyone, friends and strangers, for all the encouragement and support over the last days and months. At this point I will not publicly comment on the process or the outcome of the trial.

"However, I do ask all of you to spare a few minutes and read this letter written by the victim. To me it is unique in its form and comes as close as you can possibly get to putting words on an experience that words cannot describe. Thank you."

The pair's comments follow those shared by Turner's father, Dan Turner, in which he expressed disappointment at his son's sentencing, stating it was "a heavy price to pay for 20 minutes of action".

Turner snr.'s comments added further fuel to the fire, in a case that has prompted fierce discussion in the US, with the judge responsible for the sentencing, Judge Aaron Persky, currently facing calls to stand down.