ALGIERS (Reuters) - Algeria’s wealthiest businessman and four other billionaires close to former president Abdelaziz Bouteflika, who quit over mass protests, have been arrested as part of an anti-graft investigation, state TV said on Monday.

FILE PHOTO: Demonstrators hold flags and banners as they return to the streets to press demands for wholesale democratic change well beyond former president Abdelaziz Bouteflika's resignation in Algiers, Algeria April 19, 2019. REUTERS/Ramzi Boudina should/File Photo

The five are Issad Rebrab, considered the richest businessman in the energy-rich north African nation, who is especially active in the food and sugar refining business, and four brothers from the Kouninef family, it said.

The move came after army chief Lieutenant General Gaid Salah said last week he expected members of the ruling elite to be prosecuted for graft.

Protesters have called during two months of dissent for the removal of the elite that has governed Algeria since independence from France in 1962, and the prosecution of people they see as corrupt.

Rebrab is chairman of the family-owned Cevital company, which imports raw sugar from Brazil and exports white sugar to Tunisia, Libya and other destinations in the Middle East.

The billionaires were later brought to court to face charges from the general prosecutor’s office, the state TV channel said.

Neither they nor their lawyers could be reached for comment.

Rebrab tweeted earlier that he had gone voluntarily to a police station to discuss a matter of equipment being held up at Algiers port.

TV footage later showed a police car bringing Rebrab, who also owns the “Liberte” daily, to a court.

Rebrad is being investigated mainly over “false statements regarding the movement of capital from and to abroad, inflating equipment import bills and importing used equipment”, according to state TV.

The Kouninef family is close to Bouteflika, who ruled Algeria for 20 years. Bouteflika stepped down three weeks ago, bowing to pressure from the army and weeks of demonstrations by mainly younger Algerians seeking change.

An Algerian court has already summoned former prime minister Ahmed Ouyahia and current Finance Minister Mohamed Loukal, two close associates of Bouteflika, in an investigation into suspected misuse of public money, state TV said on Saturday.

Mass protests, which began on Feb. 22 and have been largely peaceful, have continued after Bouteflika’s resignation as many want the removal of the entire elite.

Bouteflika has been replaced by Abdelkader Bensalah, head of the upper house of parliament, as interim president for 90 days until a presidential election is held on July 4.

Hundreds of thousands protested on Friday to demand the resignation of Bensalah and other top officials.

Bensalah invited civil society and political parties on Monday to discuss the transition to elections but several parties and activists did not participate.

The army has so far patiently monitored the mostly peaceful protests that at times have swelled to hundreds of thousands of people. It remains the most powerful institution in Algeria, having swayed politics from the shadows for decades.

Salah said on April 16 that the military was considering all options to resolve the political crisis and warned that “time is running out”.

It was a hint that the military was losing patience with the popular upheaval shaking Algeria, a major oil and natural gas exporter and an important security partner for the West against Islamist militants in north and west Africa.