Mauritanian authorities released former President Mohamed Ould Abdel Aziz at dawn on Monday and placed him under surveillance a week after his detention pending an investigation on "suspicions of corruption".
Local media sources quoted one of the former president's lawyers saying: "I confirm that my client has been released and he is now at home."
"The 63-year-old former president was released on a warrant basis. He will also be placed under the direct supervision of the economic crime police; his passport was confiscated, and he was prevented from leaving the capital city, Nouakchott."
Last week, police arrested Ould Abdel Aziz, following a report issued by a parliamentary commission of inquiry that included charges of suspected corruption against the former president.
Mauritanian security forces have previously interrogated many officials and some relatives of the former president, including a notary and accountant, according to local news website Sahra Media.
Ould Abdel Aziz initially refused to cooperate with investigators and refused to answer their questions on the pretext that he is a former president. However, he later relented when he noticed the investigators' insistence on interrogating him.
Investigators said "the reason for summoning Ould Abdel Aziz is that his name appeared as a former president of the republic in files that were referred by Parliament to the Ministry of Justice, which in turn referred the reports to the Public Prosecution Office for investigation, but also because of other documents linking the former president to state security affairs."