Kingston, June 13: Jamaican sprint superstar Usain Bolt on Monday said the possibility of losing a gold medal is "heartbreaking", as his 4X100 metres relay team-mate Nesta Carter is said to have tested positive for a banned substance during the 2008 Beijing Olympics.

Carter, who helped the 4×100 team to Olympic and world championship titles, is said to have tested positive for the banned stimulant methylhexanamine during re-testing where 454 samples from the Beijing Games were used.

"I'm not too pleased about the situation. For years you've worked hard to accumulate gold medals and you work hard to be a champion, so it's heartbreaking, but it's one of those things," Bolt was quoted as saying by the BBC on Sunday.