Parliament's public accounts committee (PAC) is all set to reopen examination of the CAG report on the 2G scam by calling an official who had conducted audit of the controversial allocation of airwaves in 2008.

The PAC has decided to call R P Singh, former director general of audit (Post and Telecommunications), at its next meeting as a witness. The committee is expected to question him on the methods he used to estimate the losses in the 2G spectrum allocation.

PAC chairman Murli Manohar Joshi gave this ruling at a meeting of the committee on Monday after Congress member Sanjay Nirupam pointed to media reports which stated that the CAG had overruled a junior official in estimation of losses in the 2G scam.

Singh retired from the post on August 31. CAG Vinod Rai and deputy CAG Rekha Gupta have also been asked to explain to the committee the methodology used for calculating the 2G losses.

RTI queries have revealed that Singh, in internal communications, had pegged the 2G losses at Rs 2645 crore, much less than the presumptive loss of Rs 1.76 lakh crore stated by the CAG in its report.

Nirupam, in a letter to Joshi, had said that the questioning of CAG officials should be the sole agenda for the meeting to allow members of the committee to "comprehend" the matter and decide on the future course of action.

The PAC draft report on 2G scam had criticised the then Finance Minister P Chidambaram and raised questions on the PMO's first-come first-serve basis policy in allocating the radiowaves.