A masked hero in combat trousers and a muscle top swung into action to rescue a City worker from a knife gang as they tried to rob him in south London.

Victim Ken believes the tall, Batman-like vigilante may have stepped in to help others in Bromley, which he called "a dreadful place to walk around" at night.

Ken - who asked the Standard to withhold his surname because he has not told his family about the ordeal - was walking through Martin's Hill on Monday night when the foul-mouthed thugs "came out of nowhere" and demanded his phone and wallet.

"I thought I was quite literally done for," he said.

"Then, out of nowhere, a man about 6ft tall, dressed in black combat-style trousers and a tight muscle top, and wearing a black bandana mask, came running towards them.

"He kicked the biggest of my attackers to the ground, which must have knocked the wind out of him.

"Then he grabbed one of the others and swung him into the other one, and pushed them both into a prickly hedge. They were both screaming in pain.

"It actually scared the life out of me - as I'm sure it did the young chaps who attempted to mug me."

Ken now wants to track down the mysterious Good Samaritan so he can thank him properly for intervening.

"I only had one thought, and that was my family," he told the Standard. "I thought: 'What if I don't make it home?'"

He added his would-be muggers may have been hiding in a bush. "It all happened so fast," he said. "They were swearing, calling me names - and then one said: 'We should take his s*** from him.'"

Batman patrolled the fictional crime-ridden city of Gotham, kicking ne'er-do-wells, organised criminals and corrupt politicians into shape without revealing his face.

If you know who the masked hero is, please call the Standard news desk on 020 3615 2126 or e-mail ramzy.alwakeel@standard.co.uk.