Outgoing French President Francois Hollande attends a ceremony to mark the anniversary of the abolition of slavery and to pay tribute to the victims of the slave trade at the Jardins du Luxembourg in Paris, France, May 10, 2017. REUTERS/Eric Feferberg/Pool

PARIS (Reuters) - A French judge has questioned former French President Francois Hollande as a witness as part of the investigation into the assassination of two journalists in Mali in 2013, a member of Hollande’s staff said on Monday.

Claude Verlon and Ghislaine Dupont, both journalists at RFI radio, were kidnapped and killed in the northern town of Kidal on Nov. 2 2013 by suspected Islamist militants. Their bodies were recovered near the four-wheel drive vehicle used by the abductors.

Hollande and ex-chief of the DGSE external intelligence services Bernard Bajolet were questioned earlier this month and in December over statements the president had made in private to journalists that appeared to contradict the investigation.

France led a military campaign in January 2013 to clear Islamist militants from the north of the country after they threatened to invade the capital Bamako, an intervention that France described as largely successful.

The two reporters had been interviewing Tuareg separatists rebels before being kidnapped.