Issad Rebrab is the CEO of the Cevital industrial group and among the African richest with a net worth put at $3.7 billion as at January 2019 by Forbes. The other four are, Reda, Abdelkader, Karim and Tarek Kouninef - also Algerian billionaires.

But in atweeton Monday, Rebrab denied the arrest, saying he voluntarily answered the police's call to give evidence on a case involving industrial equipment which authorities had seized from him in June 2018.  

Their arrest, according to Algerian state TV, was as a result of their closeness to former Algeria President, Abdelaziz Bouteflika and an investigation into his government's “dissipation of public money” and “illegal privilege.”

The anti-graft agency had also received a nod to summon former prime minister Ahmed Ouyahia and current Finance Minister Mohamed Loukal. Both are close also associates of Bouteflika.

On April 2, Abdelaziz Bouteflika, who has been in power for 20 years, resigned after weeks of massive street protests.

His resignation came after the army chief of staff demanded immediate action to remove him from office.

Bouteflika has since been replaced by Abdelkader Bensalah, Head of Algerian Parliament as interim president for 90 days to prepare for a presidential election by July 4.