A 21-year-old woman suffered horrific torture while being held captive for five hours at a dwelling in Durban's KwaDabeka area, KwaZulu-Natal police said on Tuesday.

Captain Bongani Khomo said the nature of the act was "brutal, sadistic and commonly associated with the behaviour of a serial killer".

The woman was kidnapped from a roadside in KwaDabeka at the weekend by a man who took her to a dwelling in the Umhlabunzima vicinity.

"He locked her in a room, stripped her naked and then began torturing her," said Khomo.

"He heated an iron rod in fire and then inserted it into the woman's private parts."

The man took several photographs of the woman as she screamed out in pain, and then sexually assaulted her.

"After the ordeal, the woman pleaded to use the toilet. During this process, she managed to escape," said Khomo.

Police officers later accompanied the woman to the dwelling where a man was found in the company of his four-year-old daughter.

"He was positively identified and arrested," said Khomo.

Police seized the man's cellphone which contained some of the photographs that had been taken.

"Behaviour generally associated with serial killers"

The woman was taken to a hospital where she was treated by a district surgeon for severe wounds to her genitals.

Police have opened a case of kidnapping, sexual assault and assault with intent to do grievous bodily harm.

KwaDabeka police said this was the first case of its kind.

"We suspect this man may have committed this offence before but got away with it. So we are appealing to women who have had similar encounters to come forward and report it to police."

Khomo said police believed the motive was "sadism and murder".

"We believe that if she had not escaped he would have killed her, because this type of deviant and sadistic behaviour is generally associated with serial killers," he said.

The suspect is due to appear at the Pinetown Magistrate's Court on Wednesday.

The case has since been handed over to the family violence unit.