The family of a South African man held hostage in Yemen by Al-Qaeda militants made a plea on Sunday for his release, a month after a deadline for ransom passed.
Pierre Korkie has been held captive since May last year and his abductors are demanding a $3 million (2.2 million euros) ransom for his return.
His wife Yolande, who was released in January, reiterated Sunday that the South African government had "made it clear" to her that "it does not pay ransom" for kidnapped citizens and that no money has been given to a local charity or a mediator to pay Korkie's ransom.
"The family is very concerned about Pierre's situation," Yolande and her family said in a statement.
"His health is at grave risk, and without communication with the kidnappers his safety is an unknown."
The 56-year-old man is said to be in poor health, and is suffering from a hernia.
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Korkie's wife was released with the help of a mediator from one of Yemen's powerful tribes working with the local charity group, The Gift of the Givers.
"Yolande pleads with the captors to release Pierre, or to engage Gift of the Givers or the family directly with a view to come to an agreement about Pierre’s release," the family statement said.
The charity has also been working to secure Korkie's release, but month said it had lost contact with Al-Qaeda.
The couple from the central city of Bloemfontein had worked as teachers in Yemen for four years, when they were abducted in the city of Taiz by members of Al-Qaeda in the Arabian Peninsula (AQAP).
Hundreds of people have been abducted in Yemen in the past 15 years, nearly all of them by disgruntled tribesmen who freed their hostages unharmed after short periods of captivity.
The hostages are used as bargaining chips in disputes with the central government.
But AQAP, which is regarded by Washington as the global jihadist network's most dangerous affiliate, has brought a new, more threatening twist to the kidnappings.