The French priest kidnapped in northern Cameroon in November by Islamist rebels has been freed, the office of French President Francois Hollande said on Tuesday.

George Vandenbeusch, 42, was abducted from his home on 13 November near the town of Koza, about 30 kilometres from Nigeria.

Despite repeated warnings, Vandenbeusch chose to remain based in the region amid ongoing attacks carried out in the region by the Nigerian Islamist sect Boko Haram.

The kidnapping occured just as the United States designated both Boko Haram and Ansari, a splinter group, "foreign terrorist organisations".

In a brief statement, Hollande thanked Cameroonian and Nigerian authorities for their help in setting Vandenbeusch free, and the "personal involvement" of Cameroonian President Paul Biya.

French Foreign Minister Laurent Fabius was set to fly immediately to the Cameroonian capital Yaounde Tuesday to welcome and accompany Vandenbeusch back to France.

Six French nationals continue to be held hostage in Mali and Syria.