Five Jamaican athletes, including two Olympic medallists, tested positive for banned performance-enhancing drugs at last month's national championships, sources close to Jamaican athletics said.
Usain Bolt's lack of form combined with his late withdrawal from the Jamaican 100 metres national trials on Thursday have raised more doubts about the future of the world's fastest man.
Jamaican sprinter Veronica Campbell-Brown has been cleared to resume her career by the Court of Arbitration for Sport (CAS), her American-based lawyer Howard Jacobs said on Monday.
Jamaica's twice Olympic 200 metres champion Veronica Campbell-Brown was suspended by her national federation on Tuesday following a positive test for a banned diuretic at a meeting last month.