The Philippine military has been verifying reports that Islamic militants have killed a male German hostage after authorities failed to pay ransom before Sunday.

The Abu Sayyaf group abducted Juergen Kantner, 70, in November last year when he was sailing with his wife Sabine Merz on a yacht on Malaysian waters.

Merz was shot dead by the abductors, according to the military.

The Abu Sayyaf group has demanded a 30-million-pesos (600,000-U.S.-dollar) ransom for Kantner's release.

The kidnappers set 3 p.m. Sunday as the deadline for the payment of the ransom.

A military official, who declined to be named, said that an informant has told the military that Kantner was beheaded somewhere in Indanan town in the southern province of Sulu.

"We are validating the information. Our troops remain in the area of operation," the military official said.

Government authorities want to see the victim's body before confirming the reports that the captive has been beheaded.

Like the IS terrorists, the Abu Sayyaf group also uses beheading as the means of murdering their captives.

Philippine President Rodrigo Duterte has said that the Philippine-based Abu Sayyaf group has links with the IS militants in the Middle East.

Source: Xinhua