The Australian Football League (AFL) has suspended Collingwood players Lachlan Keeffe and Josh Thomas, after both returned a positive test for clenbuterol. The AFL took action after the Australian Sports Anti-Doping Authority (ASADA) informed the AFL on Friday that samples taken from both players on 10 February had tested positive for clenbuterol, which features on the World Anti-Doping Agency’s (WADA) Prohibited List.

‘The substance, clenbuterol, is not a specified substance on the AFL Anti-Doping prohibited list and as such, requires the players to be provisionally suspended’, read an AFL statement. ‘The AFL notes that only the A-sample has been tested and the players will require an analysis of their B sample in accordance with the AFL Anti-Doping Code. The testing of the B sample is scheduled for 14 April.’

Clenbuterol is prohibited for human consumption in Australia. It is a veterinary product, often used to treat asthma in horses. It is also an anabolic agent thought to promote muscle growth and weight loss, and is often used in animal feed to keep meat lean. It has a Maximum Residue Limit (MRL) set by the European Union, due to the active effect in can have on humans, however such limits are not set in other jurisdictions.

“With clenbuterol, 2,000 picograms per millimetre of urine results in an active effect”, Dutch doping scientist Douwe de Boer told World Sports Law Report. WADA has not set such a threshold limit for clenbuterol – professional cyclist Alberto Contador lost his 2010 Tour de France victory after a finding of 50 picograms per millimetre of urine.

‘Clenbuterol is a prohibited substance and there is no threshold under which this substance is not prohibited’, reads WADA’s advice on the Prohibited List. ‘At present, and based on expert opinions, there is no plan to introduce a threshold level for clenbuterol. It is possible that under certain circumstance the presence of a low level of clenbuterol in an athlete sample can be the result of food contamination. However, each case is different and all elements need to be taken into account, along with the context of the case.’

Collingwood was keen to stress that a positive test couldn’t have come from its official dietary and nutrition programme. ‘It is important for Collingwood to communicate to its supporters that the club has conducted a forensic audit of its tightly controlled dietary and nutrition program (which is overseen by its Integrity Officer) and is completely satisfied the positive results are in no way connected to the program’, read a statement. Both players have sought legal advice from the AFL Players Association.

“It was disbelief for both of them”, Collingwood Director of Football Neil Balme said in a press conference. “They’re claiming that they’re not guilty. We know what it is (the drug), which is one of the reasons why we think ‘Why would they? How would they?’ If you look at both of these players, it doesn’t make any sense for either of them to use this because they’re both quite lean.”