Calgary police are looking for a man believed to be in his 50s after a five-year-old boy was sexually assaulted while riding his bike in an alley on Elbow Drive.

Police say the boy was in the alley in the 3000 block of Elbow Drive S.W. about 10 a.m. on Saturday when he came across a man looking through garbage bins.

The two spoke briefly before the man sexually assaulted the boy.

The boy then went home and told his parents, who called police.

He was taken to the Sheldon Kennedy Child Advocacy Centre and did not suffer any physical injuries.

Responding officers took a man into custody soon after, but after further investigation, he is not believed to be responsible.

An image of the suspect was captured by CCTV cameras in the area.

The suspect is described as about 50 years old with grey hair and a short beard. He was wearing a grey jacket, dark pants and was carrying a large garbage bag.

Anyone with information is asked to call police at 403-266-1234 or Crime Stoppers at 1-800-222-8477.