Usain Bolt admits it would be a disaster if Jamaica were banned from competing at the Rio Olympics because of the doping scandal that has rocked the country.

Five Jamaican athletes tested positive for banned substances this year, including the former 100m world-record holder Asafa Powell.

The World Anti-Doping Agency (WADA) warned the Jamaican authorities they must address claims, made by a former senior official within the Jamaica Anti-Doping Commission, that drug-testing in the country is lax, or they could face expulsion from major competitions like the Olympics.

Should WADA carry out its threat, Bolt would be denied a crack at creating history by winning three straight Olympic golds over 100 metres.

“For me it would be really, really sad,” the 27-year-old said.

“It would be really bad for the sport.”

Jamaica’s Prime Minister Portia Simpson-Miller stepped in to ease concerns about her country being frozen out of the games.

She wrote to WADA, promising that testing remained a priority, and Bolt thinks that was a wise move.

“That will definitely help,” the six-time Olympic champion said at a book signing session for his autobiography ‘Faster than Lightning’.

“Anything that helps Jamaica to prove to the world that we are clean and that we are the best, I welcome fully.

“She says she is going to implement these things to make the sport better so it’s a joy for me.”

Bolt, who has always insisted he is clean, is reserving judgement on the athletes who have failed their tests until their cases are heard.

“Jamaicans are really pushing the limits and really run fast,” he said.

“I think some of the times when there are drug problems a lot of people didn’t do it on purpose but as an athlete you have to be aware and you have to take responsibility for these situations.

“There are a lot of cases going on now and we will see what comes out of them, we will see if it was done on purpose or not.”