A woman is in a critical condition after she was doused with petrol and set alight on Tuesday allegedly by her husband who also sustained burns, Johannesburg police said.

Inspector Madeleine von Wielligh said the incident took place at the couple's home in Nigel after they had an argument.

"The full details of the incident still needs to be investigated. The husband and wife sustained burns and had to be taken to hospital," said Von Wielligh.

Paramedics who arrived on the scene said the woman sustained 80 percent burns and the husband 60 percent.

Netcare 911 spokesperson Chris Botha said both patients were airlifted to the Chris Hani Baragwanath hospital.

Von Wielligh said a case of attempted murder and malicious damage to property had been opened against the husband.

"The husband will be arrested once he is released from hospital," she said.