The former Mauritanian President Mohamed Ould Abdel Aziz has been released by police after a week-long questioning over his suspected embezzlement.
He has not been charged but his passport has been taken, his lawyer said.
He has also been banned from leaving the capital, Nouakchott.
Aziz, who is 63, was arrested last week on charges of corruption.
He seized power in a coup and served two terms as president from 2008 to 2019.
Parliament started investigating his rule shortly after he left power last year.
His handling of some foreign companies as well as oil revenue and state property are being questioned.
Aziz has refused to speak to the police citing his constiutional immunity.
Several former officials have also been suspected of corruption under his rule.