A woman in her 20s was raped after catching a taxi with a man she met during a night out in Preston.
Police have stepped up patrols following the attack, which happened at a home in Ashton between 4am and 4.30am on Sunday, December 3.
'A number of officers' are now investigating, and CCTV footage of a man they want to speak to was released by the force this afternoon - along with a public appeal for information.
Det Insp Warren Atkinson, from Preston CID, said: "We are interested in speaking to this man and would urge anybody with information to come forward.”
The force said the woman was seen leaving Church Street with her attacker in a taxi, which dropped the pair off in Ashton shortly before she was seriously assaulted.
Information can be reported by calling police on 101, quoting LC-2017-12-03-1306. Alternatively, it can be reported anonymously by calling Crimestoppers on 0800 555 111.