The hunt is on for a group of men who carried out a vicious sexual assault in the New South Wales snow town of Jindabyne.

A 25-year-old man and a 22-year-old woman were attacked by a group of thugs on Thursday.

Both were knocked unconscious, and the woman was sexually assaulted.

A man and his friend were assaulted by a group of three men in Jindabyne. (9news)

The man regained consciousness while his friend was being sexually assaulted.

He was attacked again when he tried to come to his friend's aid, before he ran to the other side of the road and flagged down a passing car, prompting the attackers to flee.

Detective Inspector Tom Barnes said it was a "horrendous" attack.

The man re-lived the attack as part of the police investigation. (9news)

The two victims, from Newcastle, had spent the night at Banjoy Paterson Inn.

It was just after 1am on Thursday morning when they left the pub, and walked along Kosciuszko Road when they were set upon by the trio of attackers.

The woman was taken to Canberra Hospital but is now back home with her family.

The attack took place next to a park. (9news)

Detectives are now hunting for the offenders, though they fear they might have been holiday-goers who have already left town.

Anybody who may have captured the men on dashcam is being urged to contact police.