The Mayor of London has today been forced to retract Linford Christie's invitation to carry the Olympic torch through the capital, claiming it had been sent to the convicted drugs cheat "by mistake".

Christie, a former Olympic gold medallist, has a lifetime ban from the Olympics after testing positive for the steroid nandrolone in 1999.

However, he still received a letter signed by Ken Livingstone asking him to be one of 80 people to take the torch across the city in April as part of the build-up to this year’s Games in Beijing.

The invitation provoked a storm of controversy, before the Mayor's spokesman admitted it had been sent by mistake and without Mr Livingstone's knowledge. The Greater London Authority (GLA) issued a separate statement saying Christie was not invited after all.

"The decision to invite Linford Christie to be a torchbearer was not taken by the Mayor," he said. "The decision to invite Linford Christie was taken by officials and was a mistake."

Christie, 47, won gold in the 100m at the 1992 Barcelona games and has always denied taking the banned drug. His agent, Sue Barrett, said this lunchtime that she had a letter specifically signed by the London Mayor.

"I have a letter in front of me signed by Ken Livingstone," she told BBC Radio Five Live. "It says: 'I would be delighted if you would consider being one of our torch bearers, joining with us and up to 80 other well known personalities, who will each carry the torch for 250 metres.'"

Ms Barrett also told The Times that she had been given the invitation. "Yes, they have invited him. If he is around, he would be delighted to accept. We will know his schedule in a couple of weeks," she said.

However, the issue of who sent the invitation – and why – was mired in confusion when a Greater London Authority spokesman issued a statement saying that he had not been invited by the Mayor at all.

"Linford Christie has made it clear he will not be participating in the torch relay," the spokesman said.

"Inaccurate reports have appeared claiming that the Mayor invited Linford Christie to participate in the torch relay.

"The decision to invite Linford Christie to be a torchbearer was not taken by the Mayor.

"The Mayor only had the right to nominate five torchbearers and Linford Christie was not one of them."

Colin Moynihan, who sits on the Olympic Board for the 2012 London Games, said he was strongly opposed to Christie carrying the torch.

"I made it crystal clear that no one convicted of a drugs offence and banned for life under our bylaw should run with the Olympic flame," the BOA chairman told The Times. "I could not feel more strongly on the subject."

The GLA has officially named only Kelly Holmes, a double gold medal-winner in Athens, Sir Trevor McDonald, the newscaster, and the actress, Amara Khan, as torchbearers along the route from Wembley Stadium to the O2 Arena, a 2012 venue.