Punjab Saaf Pani Company’s (PSPC) chief executive officer, retired Capt Muhammad Usman, on Thursday resigned from his position, DawnNewsTV reported.

The PSPC is currently being investigated by the National Accountability Bureau (NAB) after the Supreme Court learned in April that the company had yet to provide a single drop of clean water despite costing Rs4 billion to the provincial exchequer.

Usman, who used to draw a salary of Rs1,465,000 as the PSPC CEO, has twice appeared before the NAB. He is being probed by the corruption watchdog as part of an inquiry into the assets of heads of public companies in Punjab.

He last appeared before the SC on July 24 when he was asked by Chief Justice Mian Saqib Nisar whether he had returned the salary he had drawn as the PSPC head.

In Usman's defence, his counsel had said that his client had an unblemished record of service and there was no allegation of corruption against him.

After he relinquished the post today, Umar Malik, the company's chief financial officer, was given additional charge.

Last year, the NAB had launched a thorough probe into the affairs of 56 public sector companies formed by the Shahbaz Sharif administration in Punjab for their alleged involvement in corruption.

These companies are accused of certain irregularities, recruitment in violation of procurement rules and merit, nepotism, and non-completion of various projects in time.

In May, NAB had grilled PML-N chief Shahbaz Sharif’s son Hamza Shahbaz in the PSPC scam, questioning his alleged role in awarding of certain contracts and making appointments despite not being a member of the board of directors.

Hamza’s brother-in-law Imran Ali Yousaf is also being investigated by the bureau for renting out an office in his plaza in Gulberg to the company on exorbitant rates.