DETECTIVES are investigating a sex attack on a woman after she got off a bus in Sidcup.

The woman, aged 23 left the bus near Crittalls Corner on the Sidcup/ Orpington borders and walked into the pedestrian underpass at the roundabout, at around 5am on Sunday (July 11).

As she made her way along the underpass she was punched by her attacker who then sexually assaulted her.

After the attack, the man ran off.

He is thought to be white and aged in his early twenties.

The assault is being investigated by officers from the Met Police's Sapphire unit, but no one had yet been arrested.

Anyone with information can call Crimestoppers on 0800 555111.