Restaurant boss saves man from Wharf dock

But he says he has no idea how the victim, in his late 20s, wearing just suit trousers and a shirt, ended up in the middle of the dock.

"We'd just finished the lunch trade when I looked across to see a group of people outside, taking photos," he said.

"I then realised there was a man in the dock and these people weren't helping him.

"I called out to ask if he was alright and a little voice said 'help'.

"So I just jumped in, fully clothed, swam out to him, grabbed hold of him and pulled him to the side. At which point security guards had got there.

"I still don't know what he was doing in there. Maybe it was a prank or a dare gone wrong."

Emergency services soon arrived and whisked the mystery man to hospital in an ambulance. Meanwhile, Mark sent for a new set of work clothes before he began greeting guests for dinner service. And he has not heard from the man or police since.

Strong swimmer Mark, 40, who opened the Italian restaurant with his brother Jon in 1994, said. "As soon as I got in the water the cold hits you and zaps the energy out of you. When I got to the guy you could tell he was really struggling.

"The paramedics asked if I wanted to go to hospital to get checked out but I was only in the water for five or 10 minutes so I said I was okay."

The incident took place at Middle Dock, between Heron Quays and Canary Wharf, at around 4.30pm on Friday, October 5.