Oscar Pistorius did not have a 'mental defect' that prevented him from knowing right from wrong when he shot dead his girlfriend Reeva Steenkamp on Valentine's Day last year, according to a psychiatrist's report.

The Paralympic champion returned to court in Pretoria, South Africa this morning following a 30-day period when he underwent mental evaluation as an outpatient at Weskoppies psychiatric hospital.

The order was made following claims by a witness during the murder trial last month that the 27-year-old suffers from an anxiety disorder.

Prosecutor Gerrie Nel told the High Court: "Mr Pistorius did not suffer from a mental illness or defect that would have rendered him criminally not responsible for the offence charged.

"[Pistorius was] capable of appreciating the wrongfulness of his act and acting in accordance with his appreciating of the wrongfulness of his act."

Pistorius has admitted to shooting his girlfriend, but denies murder by maintaining that he mistook the South African model for an intruder when he fired four shots through a toilet door at his home in Pretoria.