Police are on the hunt for a serial flasher who has indecently exposed himself in Colliers Wood on nine occasions since February 2005.

His tactic is to stand opposite a house where a light is on in the early hours of the morning, and then expose himself to the occupier once he has been spotted.

On recent occasions, he has rung the front doorbell and thrown small stones at the window to attract attention.

The incidents have mostly been reported by women aged between 25 and 35.

All nine offences took place between 12.30am and 3.30am, often on Thursdays and Fridays.

The flasher has struck largely in Boundary Road, but also in Kimble Road, Briscoe Road and University Road.

He has also been seen to walk off towards the footbridge at the north end of Boundary Road, which leads to Kenlor Road.

The man was described as black, aged between 20 and 30, and about 5ft 6ins.

His build was said to be stocky to overweight, and he has worn dark clothing and a hooded top.

He occasionally wore a baseball cap.

Police have reminded residents to close their curtains at night.

Sergeant Dean Croft, of the Colliers Wood safer neighbourhoods team, said: "If you think you see someone who may be the offender, do not make him aware of your presence. Call the police immediately using 999, stating there is a man you believe may be concerned in several indecent exposure offences at your location now."

Any non-urgent information should be directed to the safer neighbourhoods team on 020 8721 2743.