PARIS • Justin Gatlin, the 2004 Olympic 100 metres gold medallist who was suspended between 2006 and 2010 after failing a second drug test, has been tested 59 times by the US Anti-doping Agency (Usada) since his return.

According to Usada figures released on Wednesday, Gatlin - who is now dominating the world of sprinting - has been tested nine times this season.

Last year, there were 15 tests, 14 in 2013, 13 in 2012 and eight in 2011. The tests were conducted in and out of competition.

At the age of 33, Gatlin has set new personal bests in both the 100m (9.74sec) and 200m (19.57) this season.

He has established himself as the favourite to usurp Jamaican double sprint champion Usain Bolt at the biennial World Championships in Beijing next month.

Usada did not specify whether the tests carried out on Gatlin involved urine or blood.

It did not give any of the results, with the American not having been subject to any additional procedures.

After his suspension for use of testosterone, cut to four years from eight following cooperation with Usada, Gatlin officially returned to competition on Aug 3, 2010, with no testing carried out that season.

The 2005 double world sprint champion returned to win the 2012 world 60m indoor title, Olympic bronze at the London Games and a world silver in Moscow a year later.

Gatlin is also subject to tests by the World Anti-Doping Agency, national anti-doping bodies at international events and even track and field's governing body International Association of Athletics Federations.

Before the London Olympics, every athlete underwent pre-competition blood testing.

AGENCE FRANCE-PRESSE