Two men were arrested by detectives investigating the rape of a woman in Blackpool.
The men, 24 and 33 from Grantham, were held in the Lincolnshire town on Wednesday night, Lancashire Police said.
They were questioned about the sex attack, which happened at the weekend, after arriving in the resort yesterday evening.
They were later released under investigation, the force added.
Officers, who will be making further enquiries, were called by the ambulance service at around 8am last Sunday, after a 23-year-old woman said she was attacked by a man at an unknown address in Blackpool after a night out.
Police later issued CCTV images of a man they wanted to speak to, and appealed for witnesses who helped the woman to come forward.
Det Chief Insp Jon Holmes said earlier this week: "Following the attack we believe the victim first met a man described as wearing glasses and having dark hair, then a couple who escorted the woman back to her hotel.
"This is likely to have happened around 6am, but we have limited detail."