London Mayor Boris Johnson says there are no plans to make cycling helmets compulsory.

It comes after Olympic gold medal-winning cyclist, Bradley Wiggins, called for a change in the law.

"It's dangerous and London is a busy city and a lot of traffic. I think we have to help ourselves sometimes," Wiggins said at a press conference.

He was speaking after a 28-year-old cyclist was killed in an accident involving an Olympic bus.

"People should [wear a helmet] if they've got one but we have absolutely no plans to make them mandatory," Johnson said.

The Mayor added: "The evidence is mixed...in countries where they have made them compulsory it hasn't always necessarily been good for cycling and we have no plans."