Pakistan’s anti-graft watchdog on Wednesday filed a case against former premier Raja Pervez Ashraf over a Rs 22-billion scam in setting up power projects.

The National Accountability Bureau (NAB) filed a 263-page supplementary complaint against Ashraf in an anti-corruption court which will resume hearing the case on November 19.

Late last month, NAB’s new Chairman Qamar Zaman Choudhry approved the filing of a case against Mr Ashraf. The charges date back to Mr Ashraf’s tenure as Power Minister during 2008-11.

NAB had the case ready for a long time but was unable to proceed as the post of Chairman was vacant for several months.

Nine firms have been accused of receiving over Rs 22 billion as a mobilisation advance from the government to commission “rental power projects” but most of them did not set up the plants. A few firms installed the plants but after an inordinate delay.

Mr Ashraf allegedly received kickbacks and commissions when he was Power Minister and he was given the nickname “Raja Rental” for his role in the scam.

In March 2012, the Supreme Court ruled that the contracts for the power plants were non-transparent and rescinded them. Mr Ashraf, an agriculturist-turned-politician, served as premier from June 2012 to March 16 this year. Earlier, he served as Power Minister under former premier Yousuf Raza Gilani.