The rape of an 18-year-old woman in an attack in Belfast city centre 10 days ago is being investigated by the PSNI's Rape Crime Unit.
The attack took place in Gloucester Street at about 02:00 BST on Saturday 8 April.
Det Insp Zoe McKee said officers want to identify a man they believe can assist the investigation.
"He is described as around 19 years old, 5' 7" tall, thin, clean shaven with short dark hair," she said.
Police also want to hear from witnesses who saw a "distressed" woman in the area around the time of the attack.