Former Blue Bulls rugby player Joseph Ntshongwana, 34, was described yesterday as an "extremely intelligent" man, who had intentionally killed three Durban men with an axe last year.

In a hearing to determine whether he is fit to stand trial for the grisly murders, five psychiatric experts testified that Ntshongwana understood what he was doing when he allegedly committed the murders - so much so that he went as far as hiding the axe and blood-stained clothes.

The former flanker is accused of killing Paulos Hlongwa, Thembelenkosini Cebekhulu, and an unidentified man in March.

Hlongwa's head was found in a dustbin in the Durban suburb of Merebank on March 22.

Cebekhulu was killed in the city's suburb of Montclair on March 20, and the body of an unidentified man was found in Umbilo on March 23.

According to the indictment, on November 26 2010, Ntshongwana allegedly assaulted Mhleli Tholo in Yellowwood Park.

Two days later, he allegedly kidnapped a woman, held her captive at his home and assaulted her over three days before releasing her.

Ntshongwana appeared relaxed, coherent and even smiled from the Durban High Court dock yesterday. This was in stark contrast to his previous court appearances, during which he clutched a Bible, howled and appeared to speak in tongues.

On his first appearance, the Durban Magistrate's Court heard that Ntshongwana was mentally unfit to answer to the charges as he suffered from bipolar disorder and schizophrenia.

But the state's witnesses disagreed yesterday.

"I examined him between June 24 and July 21, and, during the examination, the accused was able to follow proceedings and responded correctly to questions asked. From the consultation with him, nothing indicated that he was not aware of his actions. His behaviour was intentional," said Dr John Dunn, a senior psychiatrist at Fort Napier Mental Hospital.

He said at the time of the murders, Ntshongwana was being treated for schizophrenia.

If he did not take his medication, there was a possibility of relapse but Ntshongwana would have known what he was doing, the court heard.

Specialist psychiatrist Dr Soobian Moodley testified that he examined Ntshongwana from June 24 to July 18.

"Clearly, the alleged crimes were premeditated and deliberate and from my observation he could go on for a long time without relapse. Generally, it's very unusual for people with the condition to be aggressive and violent," he said.

Psychiatrist Dr Bertram MacLear said Ntshongwana was "extremely intelligent".

"He told me that two to three years ago he began to feel distressed and became reserved from his family and friends. He became extremely religious."

MacLear said that paranoid people go on rampages without planning. "It's highly unlikely that they would carry an axe or whatever weapon around and looked for their victims.

"They would even attack people in a mall without provocation," he said.

Ntshongwana's mother is expected to give evidence today.