Maiga, 68, was detained in August over his suspected role in the purchase of a presidential plane during the rule of ex-president Ibrahim Boubacar Keita, ousted in a military coup a year earlier.

He was charged with multiple counts of graft and was awaiting trial. Lawyers maintained their client was innocent.

One of them told Reuters he died at a clinic in the capital Bamako on Monday morning, where he had been hospitalised on parole since December.

His family and doctors had unsuccessfully pushed for Maiga to be allowed to travel abroad for treatment as his health deteriorated in Bamako's main prison.

Relatives said authorities did not reply to their evacuation requests. There was no immediate response from two government spokespeople who Reuters sought comment from.

The government issued a statement later on Monday announcing that Maiga died after a "long illness" and presenting condolences to the family.

Maiga, a former defence minister, was named prime minister in 2017 and resigned two years later, four weeks after a massacre of some 160 Fulani herders by an ethnic vigilante group shocked the West African nation.