South African authorities will try to extradite an Australian flight attendant accused of involvement in a high-profile kidnapping and murder, after three men were convicted over the killing.

Johannesburg-based prosecutor Herman Broodryk confirmed to the ABC he would seek the extradition of former Jetstar air hostess Monique Neeteson-Lemkes, 38, who was the alleged mastermind behind the grisly torture and murder of South African woman Betty Ketani in 1999.

Mr Broodryk also said he would ask Australia to extradite former Queensland policeman Mark Lister, who was allegedly involved in the kidnapping of Ms Ketani.

Mr Lister has denied any involvement in the kidnapping or murder.

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Ms Ketani, a mother of three, was working in a Thai restaurant owned by Ms Neeteson-Lemkes’ father in South Africa when she went missing.

Her disappearance languished in the cold case files until 13 years later, when a letter was discovered under some carpet in a house in Johannesburg.

The letter, written by a former private detective called Carrington Laughton, said Ms Ketani was kidnapped and murdered because of a dispute over money apparently missing from the restaurant.

The letter said Ms Ketani was kidnapped and stabbed, then left for dead by the side of a road, but that she was discovered alive and taken to hospital.

The conspirators then allegedly posed as hospital staff before kidnapping her again and killing her.

The letter alleged that Ms Neeteson-Lemkes was involved in the kidnapping and eventual murder.

Australian implicated in death plot by convicted killers

Laughton and two brothers, Carel and David Ranger, were recently convicted of murder, culpable homicide and kidnapping over Ms Ketani’s killing.

Three other men were charged, but cut deals with the prosecutor and implicated Ms Neeteson-Lemkes in the planning of Ms Ketani’s murder.

Ms Neeteson-Lemkes, who was born and raised in Australia before moving to South Africa to work for her father, left South Africa in 2000 and eventually returned to Australia, where she once addressed a Federal Senate enquiry about working conditions at Jetstar.

Her Australian lawyer, David Galbally, QC, said he was aware the South African authorities were planning to apply for his client’s extradition, but that she would not comment.

In an interview with an Australian current affairs show three years ago, Ms Neeteson-Lemkes said she had no involvement in Ms Ketani’s death, but that she would not return to South Africa because she feared she would not receive a fair trial.

Both Ms Neeteson-Lemkes and Mr Lister are subject to Interpol “red notices”, which say they are wanted by South Africa for murder and kidnapping.

– ABC