Mokhtar Belmokhtar claimed responsibility for the seizure of dozens of foreign hostages at the In Amenas gas plant in Algeria in January in which more than 60 people were killed.
The Chadian claims of his death comes days after Chad's President Idriss Deby said soldiers in Mali had killed another leading al Qaeda commander in the Sahara, Adelhamid Abou Zeid.
French officials said they could not confirm the killing of either Abou Zeid or Belmokhtar.
More top news
Chatsworth House is set to reopen following the biggest restoration of the Derbyshire stately home and gardens in almost 200 years.
Vladimir Putin's spokesperson Dmitry Peskov branded Johnson’s words as 'insulting and unacceptable.'
The current UK manufacturer has said it is disappointing this "icon of British identity" is set to be awarded to a Franco-Dutch firm.