Mauritania's former president, Mohamed Ould Abdel Aziz, was on Tuesday put under "house surveillance" by a judge after he was questioned in an inquiry which has seen him charged with corruption.
It was the second time Aziz had gone before a magistrate investigating the case since the charges, including money laundering, were brought in March.
Tuesday's surveillance ruling, seen by AFP, runs for a two-month period, renewable four times.
Aziz ruled the conservative West African state from 2008 to mid-2019, when he was succeeded by his former right-hand man and ex-defence minister, Mohamed Ould Cheikh El Ghazouani.
Aziiz'z lawyers issued a statement condemning the "iniquitous" ruling.
"This victimisation is quite simply intended to prevent the ex-president benefiting from his political rights guaranteed under the constitution," the statement said.
The ex-president has said he is being persecuted in a bid to keep him out of politics, but has vowed he will not go into exile.
Aziz joined a small opposition party, Ribat National, in April in an attempt to salvage his political career after being expelled from the ruling Union for the Republic (UPR) party, which he had founded
Ribat also put out a statement against the ruling which deepens his difficulties under the El Ghazouani presidency.
One of Aziz's sons-in-law, two former prime ministers, five former ministers and four businessmen are also under investigation.
The 64-year-old former general who came to power in a coup already had to report to police three times a week and to seek approval before leaving the capital.
The charges followed a year-long probe initiated by parliament into the handling of oil revenue, the sale of state property, the winding up of a publicly owned food-supply company and the activities of a Chinese fishing firm.
A state prosecutor involved with the investigation in March said cash and assets worth the equivalent of about 96 million euros ($115 million) had been seized.