Oscar Pistorius did not have a mental disorder when he killed his girlfriend, a psychological report said as his murder trial resumed.

"Mr Pistorius did not suffer from a mental illness or defect that would have rendered him criminally not responsible for the offence charged," said state prosecutor Gerrie Nel, reading from the psychologist report.

The prosecution requested the evaluation after a defence witness said the double amputee was suffering from Generalised Anxiety Disorder(Gad).

Mr Pistorius, 27, underwent a month of tests as an outpatient at Weskoppies psychiatric hospital in Pretoria.

He has often displayed his emotions during the trial, and has sobbed and vomited in court.

There are no juries at trials in South Africa, so the athlete's fate will ultimately be decided by the judge, assisted by two assessors.

If found guilty of murder, Mr Pistorius, who went on trial on 3 March this year, could face life imprisonment. If he is acquitted of that charge, the court will consider an alternative charge of culpable homicide, for which he could receive about 15 years in prison.