Textiles Minister Dayanidhi Maran stepped down after being named in a police court report that suggested he abused his powers in the 2006 sale of second-generation (2G) mobile phone licences when he was the telecom minister.

Maran’s departure is the latest setback for Singh, whose upright image has suffered as a series of graft scandals have buffeted his administration over the last year.

CBI officials told India’s top court Wednesday that Maran prevented the company, Aircel, from obtaining crucial cellphone spectrum licenses until it was sold to Maxis Communication, the Economic Times newspaper reported.

Prosecutors earlier charged another former telecommunications minister, Andimuthu Raja, with fraud and forgery in a separate scandal related to the 2008 sale of cellular licenses.

That sale, conducted on a first-come, first-served basis, netted India only 124 billion rupees ($2.7 billion), causing the government to lose as much as $36 billion in potential revenue, according to the state auditor general.

Both Raja and Maran belong to the Dravida Munnetra Kazhgam, a powerful regional party that lost recent state elections in Tamil Nadu in the wake of the scandal. The party is a coalition partner of Singh’s government in New Delhi.