A 22-year-old man was raped in an alleyway in central Glasgow after he left a nightclub in the early hours of Sunday (24 September).
The sexual assault took place at around 3.40am in a lane between Parnie Street and the busy shopping street Trongate.
The victim encountered his male attacker as he left a nearby nightclub. Police are appealing for witnesses to come forward and are reviewing CCTV footage to try and identify the suspect, who is described as being black.
Detective Inspector David Reilly said: "The victim has been left extremely distressed by what happened and it is vital that we trace the individual responsible.
"I would appeal to anyone who was in the surrounding area in the early hours of this morning who may have seen anything suspicious to please get in touch."
"Anyone with information is asked to contact the Public Protection Unit based at London Road via 101 and quote incident number 1051 of Sunday 24th September 2017," he added.