Ahmed Ouyahia and Abdelmalek Sellal both served under former president Abdelaziz Bouteflika.
APS said they were involved in a corruption scandal and accused of covert financing of Bouteflika's final re-election bid.
The new proceedings in the capital Algiers come after the supreme court in November accepted a defence appeal.
Several former ministers and other well-known figures are also on trial over the same affair, APS said.
The trial of Ouyahia and Sellal in December 2019 was the first in a series of high-profile corruption cases launched after Bouteflika resigned earlier that year.
It was also the first time since Algeria's independence from France in 1962 that former prime ministers had been put on trial.
Ouyahia was prime minister four times between 1995 and 2019, and had been sentenced to 15 years behind bars.
Sellal, who served from 2012 to 2017 and managed four of Bouteflika's election campaigns, was sentenced to 12 years in jail.
Their sentences were confirmed on appeal in March.
The pair were sentenced to further jail time in separate cases last year.
Bouteflika, who was Algeria's longest-serving president, was forced to resign in April 2019 after losing the backing of the army amid enormous street protests against his decision to seek a fifth term.
Following his departure, authorities launched a string of investigations against high-ranking former officials and business figures, several of whom have been convicted.
Some see the trials as little more than score-settling between rival clans among the ruling elite, however, rather than a genuine reform effort.