Two former powerful Algerian officials and a prominent businessmen were questioned in courts on Sunday, state TV said, over accusations of corruption in the ruling elite under ex-president Abdelaziz Bouteflika.
Algerian former prime minister Ahmed Ouyahia appeared in a court in Algiers to be questioned over alleged corruption involving the partner in Algeria of Germany's Volkswagen.
This is the second time Mr Ouyahia has been questioned since the Supreme Court last week ordered his detention as part of another investigation into alleged corruption.
Algeria's former finance minister Karim Djoudi also appeared before the Supreme Court to face questions about corruption accusations.
He has not been charged but joins a series of senior figures associated with former president Abdelaziz Bouteflika to face investigations since protests broke out this year demanding the departure of the ruling elite.
The channel later said Mourad Eulmi, the head of the Algerian family-owned firm Sovac which runs an assembly plant with Germany's Volkswagen AG, was questioned in another court in Algiers about corruption accusations.
Mr Eulmi was arrested by police last week. The TV reports did not give any more details about Mr Djoudi and Mr Eulmi's cases and there was no immediate statement from the men or any lawyer representing them.
The hearings came days after the Supreme Court ordered the detention of ex-prime ministers Ahmed Ouyahia and Abdelmalek Sellal, as well as former trade minister Amara Benyounes for "dissipation of public funds and awarding illegal privileges".
The army is now the main player in Algerian politics after Mr Bouteflika stepped down two months ago and its chief of staff Ahmed Gaed Salah has urged the judiciary to speed up the prosecution of people suspected of involvement in corruption cases.
The legal moves have not prevented further demonstrations by protesters pushing for radical change and a clean break with an elite who have governed the North African country since independence from France in 1962.
Mr Djoudi served as finance minister under Ouyahia from June 2007 to May 2014 when he resigned on health ground before being named Mr Bouteflika's adviser for the past two years.
Mr Bouteflika stepped down on April 2 under pressure from the army and protests that erupted on Feb.22.
Mr Bouteflika's youngest brother, Said, and two former intelligence chiefs have been placed in custody by a military judge for harming the army's authority and plotting against state authority.
Several prominent businessmen, some of them close to Mr Bouetflika have been detained at a prison in Algiers over corruption allegations.
Protesters are now seeking the departure of interim President Abdelkader Bensalah and Prime Minister Noureddine Bedoui, both seen as part of the establishment.
Authorities have postponed a presidential election previously planned for July 4, citing a lack of candidates. No new date has been set for the vote.