A witness in the trial of a woman dubbed the "black widow" has revealed how her friend arrived home with a deceased medic's Mercedes-Benz, claiming it was a gift from her stepfather.

Ntokozo Hlatshwayo, who rented a room with Malibyane Maoeng, 30, in Daveyton at the time she was arrested in connection with the death of doctor Godfrey Sankubele Dire, 62, told the Benoni regional court that she learnt about the medic's death with shock.

She said she witnessed Maoeng use Dire's credit card to buy furniture for a new apartment, two days after arriving with the flashy car.

Hlatshwayo helped the police find Maoeng, who had been on the run after she was last seen with Dire at a lodge where he was found dead.

She told the court yesterday that Maoeng, who had left the lodge with Dire's white Mercedes-Benz, had told her almost everything.

Maoeng is on trial charged with possession of a stolen vehicle, theft and fraud.

"I knew doctor Dire because he frequently came to see her using different cars, and I also knew her two late boyfriends.

"I witnessed the death of Louis Mphaphathe who was found dead on the pavement in Daveyton, outside where we rented. I also knew the Malawian guy, Yotamu, who also died of suspected poisoning."

Hlatshwayo said she knew about Maoeng's affair with Dire, but didn't think she would steal his car and leave him for dead in a lodge.

"After she came with the car, she also asked me to accompany her the next day to go buy furniture. Two days later, we helped her move to a newly-rented apartment in Benoni," she said.

She said she was with Maoeng as she used the late medic's credit card to buy furniture.

"On the night when she arrived with the car, she asked one of the male tenants to park the car for her as she could not properly drive, then later called her ex-boyfriend to keep the car for her after realising she could not keep the car at rooms where we rented," said Hlatshwayo. "She told the person on the other side of the line that she was coming with a stranger who was not supposed to know what was happening with the car."

Hlatshwayo also told the court that Maoeng had arranged with a certain female in Soweto to help her remove the tracker from the vehicle.

Maoeng previously told the court that the late doctor was her blesser who allowed her to use his credit cards.

Maoeng also told the court that he had borrowed her the car and that she had left him alive at the lodge.

"After all these incidents, I became scared of her and decided to speak up because I did not want be held accountable for being an accomplice to her crimes," said Hlatshwayo.

Hlatshwayo said she decided to open up to the police when they came looking for her repeatedly.

"I realised that she was a criminal when she moved out shortly after she came with a white Mercedes Benz, claiming it was a gift from her stepfather," said Hlatshwayo.

Another witness, who is an employee at the lodge where Dire's body was found, Sana Mayengisa, told the court that she was the one who discovered his body.

"I came at around 7am on June 30th and went to collect linen in the doctor's room, but I went out because I thought he was sleeping," said Mayengisa.

Mayengisa said after the staff realised that the doctor had not requested anything to eat or step out of his room, they got curious.

"We got suspicious around 11am when all staff on duty confirmed that he had not came out of the room since the previous day," she said.

Mayengisa said they took the spare key, because the room was still locked and opened the door to the late medic's room.

"I called him three times and said 'doctor, doctor, doctor', but he did not respond, so I uncovered the sheet and found him dead with froth coming out of his mouth," said Mayengisa.

Prosecutor Basil Marishane asked that the trial be postponed to September 3.