The attack happened at around 1am on Sunday when a 25-year-old was approached by another man as he walked on Brooms Road at its junction with Millburn Avenue.
Detectives say the victim was forced to a nearby grassy area where he was subjected to a serious sexual assault.

The attacker then fled along Brooms Road in the direction of Morrisons supermarket.
He is described as being around 6ft 1in, with a stocky build and a possible foreign accent. He was wearing dark clothing and a hooded top.
Detective Inspector Scott Young said: “A young man has been subjected to a terrifying sexual attack and extensive inquiries are under way to find whoever is responsible for this utterly despicable crime. I would like to speak to anyone who was in the area near to where Brooms Road meets Millburn Avenue between midnight and 2am on Sunday morning. Whether you saw a man matching the description of the suspect, a man following another man, or a man in a state of distress – if you saw anything out of the ordinary at all then please come forward.”