Justin Gatlin (l) is facing some tough questions [GALLO/GETTY]

Olympic 100 metres champion Justin Gatlin has been banned for four years pending a possible appeal for a 2006 positive test for testosterone.

The decision by a three-member U.S. arbitration panel, which has not been announced publicly, could end the career of the 25-year-old Gatlin if he does not successfully appeal to the International Association of Athletics Federations (IAAF) or the Court of Arbitration for Sport (CAS).

The Washington Post reported on its website that two out of the three American Arbitration Association arbitrators had said they could not give less than a four-year ban because of a previous positive test.

A third dissented, the Post reported.

Gatlin could not be reached for comment.

His lawyer, John Collins, declined to comment.

Gatlin failed a drugs test in 2001 for a prescribed medication for Attention Deficit Disorder.

He was reinstated by the International Association of Athletics Federations the
following year.

The American won the 2004 Athens Olympic 100 metres title and completed a 100-200 double at the Helsinki world championships in 2005.

He won each of his five 100 metres competitions in 2006, including tying the then world record of 9.77 seconds in Doha and winning the U.S. title.

But after it was announced that Gatlin had returned a positive test for the male sex hormone testosterone at the 2006 Kansas Relays he was suspended while his case was referred to arbitration.

Source: Agencies