The family of a South African held hostage by militants in Mali for over five years launched a fresh appeal for his release Saturday, just days after a French journalist was freed.

Gerco van Deventer, 47, was kidnapped in Libya on November 3, 2017 on his way to a power plant construction site around 1,000 kilometres (600 miles) south of the capital Tripoli.

Three other Turkish engineers also seized at the same time as him were freed seven months later. Van Deventer remained in captivity and was moved to Mali.

"I'm launching a fresh appeal... we desperately need him home, he's a father of three children," his wife Shereen van Deventer, told AFP in an online interview.

"It's a difficult situation for us as a family, we would really ask for ... their (captors) compassion to release him," she said speaking from the small town of Swellendam, 220 kilometres east of Cape Town.

Van Deventer, an emergency paramedic who was working for a security company, is the only South African citizen held hostage by a non-state actor in the Sahel, according to the wife.

The new calls for his release came after the freeing of French freelance journalist Olivier Dubois, 48, and 61-year-old American aid worker Jeffery Woodke -- respectively kidnapped in 2021 and 2016.

Shereen van Deventer, 39, said Dubois's "release certainly provides us with renewed hope for Gerco's release".

"There's that hope that there's that door being opened," she said.

In his post-release interview with Radio France Internationale (RFI), Dubois said he spent slightly more than a year with van Deventer in captivity.

"He's in his sixth year. He doesn't deserve this, he needs to go home," Dubois said.

There was flurry of negotiations for his release during the first few years after his kidnapping, but the Covid-19 pandemic put brakes on the efforts until early this year, said the wife.

Several people are involved in negotiations, she said, adding that the government told her it was still trying to get her husband back home.

A spokesman for the South African foreign affairs ministry told AFP that "negotiations are still ongoing, we are trying to get him out".