Burundi's former President Pierre Buyoya died on Thursday, a family member and an official said on Friday.

"The death of former president Pierre Buyoya is confirmed. There is no more doubt," head of information and communications division at Burundi's office of the President Willy Nyamitwe said in a tweet.

Buyoya's sister-in-law, who spoke on condition of anonymity, told Reuters Buyoya had died on Thursday en route to Paris for medical treatment. She did not give any further details.