Officers initially arrested a 23-year-old local man but he has since been ruled out in connection with the offence.

The victim was attacked at about 8pm on Saturday after going to the temporary block of communal toilets set up on the beach, close to The Spa.

In the toilets she was confronted by a man who sexually assaulted her before walking out of the toilets and headed towards the sea.

The victim was comforted by an unknown woman while event security and the police arrived on the scene.

Detective Inspector Ian Dyer, who is one of the senior officers leading the investigation, said: "At this time the original suspect is being discounted from being a suspect for the offence."

The attacker is described as white, in his early 20s, with "piercing" aqua blue eyes, brown hair and a square jaw. He was wearing a blue, round neck T-shirt with a white graffiti-style motif on the front.

DI Dyer said he wanted to speak to anyone who was in the area of the toilet block around the time of the attack, anyone who may have spoken to the victim or anyone who saw a man acting suspiciously or leaving the area in a hurry.

He added: "The victim spoke to several girls prior to going to the toilets. They weren't her friends and I don't know who they are, but they may have seen something or she may have said something to them prior to the incident."

DI Dyer said this sort of incident was "an exception" and said organisers of Beached had fully co-operated with the investigation. He said: "They have provided us with all the information we have requested."

At the time of the assault the beach area was packed with people and the band performing on the main stage was called The Ryes. Police inquiries and a forensic examination are ongoing.

If you have information, contact Scarborough CID on 0845 6060247 or Crimestoppers anonymously on 0800 555111 with information.