LONDON - The International Association of Athletics Federations (IAAF) has asked the Court of Arbitration for Sport (CAS) to double Olympic 100 metres champion Justin Gatlin's four-year doping ban.

The International Association of Athletics Federations (IAAF) has asked the Court of Arbitration for Sport (CAS) to double the four-year doping ban on Olympic 100 metres champion Justin Gatlin, pictured in 2006. [Agencies]

A US arbitration panel suspended the 26-year-old American for four years in January after a positive test for the male sex hormone testosterone in 2006.

The panel ruled that the positive test was a second offence after Gatlin tested positive in 2001 for medication to treat Attention Deficit Disorder. He was reinstated by the IAAF in the following year.

"The IAAF's view is that Justin was publicly informed after he committed the first doping offence that any repetition could lead to a life ban," IAAF spokesman Nick Davies said on Monday. "We are not prepared to accept a reduction to four years."

Gatlin has also appealed to CAS and asked for a ruling before the end of May.

If the independent Lausanne-based body decides the ban should have been two years, Gatlin could compete in the Beijing Olympic trials in the following month.