A 21-year-old British woman was raped on a beach close to FIB music festival in Benicassim last weekend.
The victim was found at around 1.00am on Saturday on Torreon beach, in the resort town just one hour north of Valencia.
She was discovered in a disorientated state by a group of young people who called the police.
The woman was taken to Castellon General Hospital where her injuries were treated.
She was unable to provide many details about her attacker and told Guardia Civil officers she does not remember the attack clearly.
The Spanish press reported that detectives had been unable to draw up a photofit of the suspect because the victim’s memory was affected by alcohol, but they are examining her clothes and the beach for forensic evidence.
Local officials stressed the attack did not take place within the festival grounds and denied it was linked.
Benicassim Ayuntamiento said it was not clear if the victim had been at the music festival or was simply on holiday in the area.
Record numbers of police were on patrol during the festival, which featured acts including the Red Hot Chili Peppers, Liam Gallagher, Kasabian and Stormzy.
Some 50,000 fans a day, around half of whom are British, attend the four-day festival.
Police upped their numbers by 30 per cent this year amid concerns about potential terror attacks.