An accountability court on Wednesday summoned all accused in the Rental Power Projects (RPP) case, including former prime ministers Raja Pervaiz Ashraf and Yousuf Raza Gilani, on April 23.
The accused persons would be indicted in the next hearing of the case.
Meanwhile, former premier Ashraf and former finance minister Shaukat Tareen appeared in the court.
The accountability court was also hearing the Oil Gas and Power Regulation Authority (OGRA) corruption case during which former OGRA chairman Tauqir Sadiq and another main accused Dewan Ziaur Rehman appeared in the court. Dewan Ziaur Rehman is accused of corruption amounting to Rs 52 billion.
NAB has been investigating 12 RPPs cases in which nine firms reportedly received more than Rs22 billion as mobilisation advance from the government to commission the projects, but most of them were accused of failing to set up plants.
The bureau has already recovered Rs13 billion in the case.
While Raja Ashraf was a former federal minister for water and power also the head of the selection committee which had approved it in OGRA references.
Moreover, Yousuf Raza Gilani was charged by the NAB with illegally appointing former OGRA chairman Tauqeer Sadiq in 2009. However, Gilani was of the view that since he took this decision as prime minister, it could not be challenged while he was in office.
