French President Francois Hollande has confirmed that a body found in northern Mali was that of hostage Philippe Verdon and vowed the killing would not go unpunished.

The French geologist, who was kidnapped by Al-Qaeda in the Islamic Maghreb (AQIM) from a hotel while on business in northeastern Mali in November 2011, was already believed to be dead.

Confirming his death on Monday, Hollande said: "Those responsible for the death of our compatriot must be identified and brought to justice."

"The remains will be transferred to our country as soon as possible and autopsies will allow us to know the cause of death."

We will then determine the cause of death and nothing will go unpunished

Francois Hollande, French president

Verdon's captors announced in March that the 53-year-old had been executed in response to France's military intervention in Mali.

Hollande had said earlier that a body believed to be that of Verdon had been found 10 days earlier in northern Mali and that officials were doing "everything possible" to confirm the identity.

"We will then determine the cause of death and nothing will go unpunished," Hollande said at Mali's embassy to Paris, where he was awarded the highest rank in the country's National Order.

At least seven French citizens remain captive in Africa, with another two in Syria.

"I am aware of the anguish of the families with loved ones still held hostage in the Sahel, and I wish to reassure them that the government is continuing to work full-out to obtain their release and their return to France," Hollande said.

France sent 3,000 troops to Mali, its former colony, in January to help the weak Malian military drive out al-Qaeda-linked rebels who had seized control of the country's north.

Source: Agencies