Nesta Carter (right with Usain Bolt) was told of the adverse finding in May - before the Rio Olympics

Usain Bolt says his legacy has not been tarnished by having to hand back one of his nine Olympic gold medals after Jamaican team-mate Nesta Carter tested positive for a banned substance.

The 30-year-old also says he does not have a problem with Carter, who was part of the Jamaican quartet that won the 4x100m in Beijing in 2008.

"It's rough that I have to give back one of my medals," he told Reuters.

"I'm not happy, but it's just one of those things that happen in life."

Bolt completed a 'triple triple' in Rio last summer, winning gold in the 100m, 200m and 4x100m relay to add to his successes in the same events in 2008 and 2012.

"I think I've still accomplished a lot - it hasn't changed what I have done throughout my career," said the 100m and 200m world record-holder. "I have worked hard and pushed and done things that no-one has done before."

Carter, 31, was also part of the squad that won the event in London five years ago and helped Jamaica win at the World Championships in 2011, 2013 and 2015.

A retest of his sample from the 2008 Games was found to contain a banned stimulant.

He ran the first leg in Beijing for Jamaica's sprint relay team, which also included Bolt, Michael Frater, Asafa Powell and Dwight Thomas, who ran in the heats.

"I'm not going to despise anybody for anything," Bolt told The Gleaner. external-link "Nesta and I are still friends. We came up through the ranks in high school, so we're still friends, and I really don't have a problem with Nesta."

The Jamaican Olympic Association may appeal against the decision, while Carter's lawyer confirmed on Wednesday that the sprinter will lodge his own appeal with the Court of Arbitration for Sport.

Bolt was non-committal about whether he would financially contribute to Carter's appeal.

"That's up to my management, there are a lot of variables so we will discuss that and see where we go from there," he added.