Algeria's richest man Issad Rebrab has been detained in jail on the public prosecutor's orders, state media reported on Tuesday a day after his arrest as part of a corruption probe.
The crackdown on alleged graft follows the resignation of veteran president Abdelaziz Bouteflika in early April after weeks of mass protests against his 20-year rule.
Rebrab, the 74-year-old chief executive of Algeria's biggest privately-owned conglomerate Cevital, was placed in detention overnight according to the APS news agency.
Forbes magazine lists Rebrab as Algeria's richest man and the sixth-wealthiest in Africa, with a net worth of $3.38 billion in 2019.
He is "suspected of having made fake statements concerning the transfer of funds to and from abroad," APS reported.
He is also suspected of having imported "used equipment" despite enjoying tax and customs breaks made available by authorities for the purchase of new material.
Earlier on Monday, Rebrab tweeted that he had gone voluntarily to a police station to discuss "equipment that has been held up at the Algiers port since June 2018".
Cevital, which he founded, employs 18 000 people and is active in electronics, steel and food, and in recent years acquired businesses in France.
According to Forbes, Cevital also owns one of the largest sugar refineries in the world with the capacity to produce two million tonnes a year.
Rebrab, who last month said he backed anti-Bouteflika protests, is one of a number of tycoons detained in graft investigations since the president stepped down.
The arrests come after army chief Ahmed Gaid Salah called on prosecutors to "accelerate the pace" of corruption probes into those with ties to Bouteflika's inner circle.
Late on Sunday four brothers from the influential Kouninef family were arrested, according to state television, in relation to a probe into non-compliance with state contracts.
Prosecutors are investigating "insider influence to obtain undue advantages and misappropriation of real estate," according to the broadcaster.
Abdelkader, Reda, Karim and Tarek Kouninef have dealings in everything from agribusiness to civil engineering.
The family is said to be close to Said Bouteflika, the younger brother and former advisor of the president.
On Monday state television reported the current finance minister, Mohamed Loukal, and former prime minister Ahmed Ouyahia had been summoned for questioning by a magistrate in connection with the alleged misuse of public funds.
The latest developments follow the arrest late last month of Ali Haddad, one of Algeria's top businessmen and a Bouteflika backer, who had tried to cross the border into Tunisia with two passports and undeclared currency.
The day after he was detained, prosecutors announced graft probes into unnamed individuals and banned corruption suspects from leaving the country.
Algerian media has reported around a dozen businessmen are under investigation, all with ties to Bouteflika's entourage.