A teacher was allegedly shot dead by her boyfriend at their home in Naturena, south of Johannesburg, on Friday night.

Mihlothi Ngobeni, 44, a teacher at Eldomaine High School in Eldorado Park, died at the scene.

Independent Police Investigative Directorate (Ipid) spokesperson Moses Dlamini said the suspect, who was a Visible Policing warrant officer at Eldorado Park police station, accused Ngobeni of attacking him with a knife after he received a call from a lady.

"The suspect said there was a struggle and a shot was accidentally discharged. A bullet hit the deceased on the upper neck and exited on the left temple. The suspect allegedly phoned the ambulance but the deceased was certified dead.

"The suspect was immediately arrested and charged with murder," Dlamini said.

"He said the incident happened when the suspect arrived home just after 8pm to find his wife drinking in the company of a neighbour.

"He was surprised to find her drinking as he knew her to be a Christian, but he let it go when she said she just wanted to be happy.

"The problem started when the suspect received the call [from a woman] and it is alleged Ngobeni smashed the suspect's phone on the floor."

On Monday, the school had a white candle and a rose at the reception to honour Ngobeni.

Deputy principal Shaheen Ramlah said they were disturbed by the news of Ngobeni's passing.

"She started with the school on February 1 2012 and she believed in doing her work. She was loved by her pupils [and] when we conveyed the message of her death, the school could not continue as normal.

"Pupils took her death very hard. When she left on Friday she was her usual bubbly self, we did not think anything was bothering her," Ramlah said.

Ramlah said Ngobeni's family was preparing to take her body to Limpopo where she came from.

"They told the school that it is still very early to talk about the incident," Ramlah said.