Jamaican sprinters Asafa Powell and Sherone Simpson are free to resume racing after the Court of Arbitration for Sport(CAS) reduced their 18-month doping bans to six months on Monday.

Powell, the former 100-meter world record holder, and three-time Olympic medalist Simpson tested positive for a banned stimulant oxilofrine at Jamaica's national championship last June.

In April, Jamaica Anti-doping Disciplinary Panel suspended the two athletes for 18 months, with the start of the sanctions backdated to June 21, 2013.

Both athletes had appealed to the CAS that their suspensions be reduced to three months, arguing the offence committed was "minor".

After a two day hearing in New York last week, CAS announced Monday that it had decided to reduce their period of ineligibility to six months, which has been already served.

"I never felt that I should not have received a sanction. However, I always felt that the 18 months was not in line with a first-time positive test result," Powell said in a joint statement released with Simpson on Monday.

"I feel total relief and that we have finally been vindicated," Simpson said, "Our actions were not intentional and CAS has recognized that. I am truly thankful."

Powell and Simpson are eligible to compete immediately and they said both of them will be back on the track on Tuesday "with a renewed sense of excitement and passion".

"They cannot wait to hit the track and fly the Jamaican flag high," according to Powell's publicist Tara Playfair-Scott.

This is the third case involving Jamaican athletes which CAS has overturned.

In February, CAS cleared a two-year ban imposed on the two-time Olympic 200m champion Veronica Campbell Brown because of "deplorable" flaws in the test collection procedures in Jamaica.

And in May, Dominique Blake, another Jamaican sprinter, had her drug ban reduced from six to four and a half years by the CAS.