Najwa Petersen looked suspiciously "normal" only hours after her husband Taliep's funeral, one of Taliep's sisters told the Cape High Court on Thursday.

And she did not give a convincing answer when asked whether she was involved in the theatre personality's murder, Ma'atoema Groenmeyer said.

She was giving evidence in the trial of Najwa and three men the widow is alleged to have hired to kill Taliep on the night of 16 December 2006.

Groenmeyer, who said she had had a close and loving bond with Najwa, told the court that about two weeks after the killing she asked Najwa what happened that night.

Najwa told her she woke to see a man with a gun pointed at Taliep's head, that she gave the robbers money from a safe, and that the last time she saw Taliep alive he was being forced to kneel in the family's television room.

Groenmeyer said she then told Najwa she wanted to ask her a question that was hypothetical, not because she was suspicious.

She asked Najwa whether, if Najwa had been involved in the killing, she would be able to tell her.

"And Najwa looked at me and she said, unh, unh, shaking her head.

"That wasn't the answer I wanted. I wanted a convincing answer," Groenmeyer said.

"I also said to Najwa, you don't cry, you don't say you miss him."

She said though Najwa had been in psychiatric hospitals more often than out in the year preceding the killing, she was "fine" after Taliep's death.

"In fact on the day, two hours after my brother was buried, Najwa was already acting like a normal person, smoking a cigarette, purdah [face veil] and headscarf off."

Groemeyer said that she now believed that Najwa's family, the Dirks, were behind the murder.

Another witness, Mymuna Bedford, told the court how at Najwa's request she obtained the cell number of Fahiem Hendricks, the man who told the court earlier in the hearing that he was a key link in Najwa's arrangements for the murder.

Bedford said she had known Najwa and her family for 25 years, and had had a "sisterly" relationship with her.

Hendricks's family lived two roads away from her in Crawford on the Cape Flats, though at the time she only knew his brother.

Bedford said she encountered Hendricks for the first time only after the killing, when he came to Najwa's house when she was still in the Muslim period of mourning.

In that period a woman is not supposed to see men other than her immediate male relatives.

Without asking who he was, and despite Najwa's protestation of "no it's fine", Bedford told him he was not allowed to be there, and escorted him out.

She did this to protect Najwa's name under the mourning taboo.

Later she was interviewed by police, who asked her if she knew Najwa was having an affair with Hendricks.

She told them the idea was absurd, because she knew how much Najwa loved Taliep.

However, she went to confront Najwa, and asked her who the police were talking about.

Najwa's domestic worker, who was listening, said it was the man she threw out of the house.

"I said, that piece of shit, I wouldn't ever put my lips on him. I know you better than that," Bedford said.

"You're supposed to have more class than that, that's classless."

However, Najwa assured her there was no affair, and also swore on her father's life that she had nothing to do with Taliep's murder.

Her father, Suleiman Dirk, has since died in a car accident.

The case continues on Friday.