The former Mauritanian president Mohamed Ould Abdel Aziz has defended his innocence over suspected embezzlement.
Aziz was released by police early on Monday after being questioned for a week.
He has called the procedure illegal and said it is aimed at damaging his image as former president.
"No charges are brought against me. I spent seven days in arbitrary and unjust detention while I voluntarily came in my car to the safety of the State," Aziz said.
Aziz, who is 63, seized power in 2008 and served two terms as president.
He was succeeded by his right-hand man and defense minister in August 2019.
He is suspected of "maladministration and embezzlement of public assets."
After he failed to answer a call to testify before the commission of inquiry in July, MPs approved a law to empower a High Court of Justice to try presidents and ministers in cases of "high treason".