Oscar Pistorius's defence lawyer Barry Roux has been heard telling his opposite number that he is going to "lose", after a South African court heard prosecutors appeal against the Paralympian's conviction.
The state delivered their case at the Supreme court in Bloemfontein, arguing that Pistorius should have been convicted of murder.
The double amputee was found guilty of culpable homicide (manslaughter) after shooting dead his girlfriend Reeva Steenkamp in the early hours of Valentine's Day in 2013.
Pistorius, who claimed that he had mistaken Steenkamp for an intruder when he fired four gunshots through a toilet door, has served less than a year in prison before being released and put under house arrest.
According to South African news site News24, broadcasters' microphones picked up Roux saying to prosecutor Gerrie Nel in Afrikaans: "But that I am going to lose is a fact."
It is not clear whether Roux was referring to the appeal as a whole or a different matter when the comment was made.
If the appeal is successful, Pistorius is likely to return to prison.