South African heavyweight boxer Francois Botha - the man seemingly robbed of victory in his fight against Sonny Bill Williams - has reportedly tested positive for two banned substances.

Australia's Channel 9 is reporting that a blood sample collected a few days before the bout has shown Botha used phentermine, which is an appettite supressant that can lead to hostility and "and urge to attack", and benzodiazepines, a muscle relaxant. Both are on the WADA (World Anti-Drug Agency) banned list.

The network suggests Williams may now get more credit for a performance that was already shrouded in controversy. The fight was scheduled for 12 rounds, the bout was apparently shortened to just 10, with some claiming Botha's camp was only notified late in the fight.

Botha, 44, has tested positive before - for the steroid nandrolone - after his win over German Axel Schulz in 1995. His camp claimed he had been prescribed the drug for an arm injury. The fight was declared a "no contest" and the IBF does not recgonize him as a former champion.