New Delhi, Nov 15 (IANS): India's top government auditor Vinod Rai will depose before the Joint Parliament Committee (JPC) Tuesday, a day after his former colleague contradicted the controversial 2G audit report saying the presumptive loss of Rs.1.76 lakh crore in the radiowave allocation was only a "mathematical guess".

Rai will be asked about the differences of opinion within the Comptroller and Auditor General (CAG), after R.P. Singh, one of the key auditors in the 2G case, told the multi-party parliamentary probe panel that the loss suffered in the sale of scarce radiowave spectrum was only Rs.2,645 crore.

Singh, then director general of audit, post and telecommunication, who retired Aug 31, explained to the JPC that his calculation in a draft audit report was based on inflation rate of seven years as the entry fee decided in 2001 was not revised in 2008.

But the final audit report put the figure at Rs.1.76 lakh crore, calling it presumptive loss on the basis that the scarce telecom spectrum should have been auctioned.

Rai's deposition is significant because he is expected to counter Singh, who also alleged on Monday that he was asked to sign the final audit report even as he disagreed with much of its content.

Sources told IANS that Rai has urged the JPC to have Singh present in the meeting when he deposes before the panel.

Appearing before the JPC, Singh said quantification of loss was not part of the objectives of the CAG audit and the final figure of Rs 1.76 lakh crore was at best a "mathematical guess".

According to JPC chairperson P.C. Chacko, the former CAG official maintained that the loss due to allocation of 2G spectrum could not be calculated as auction was neither recommended by the telecom watchdog, TRAI, nor contemplated by the government.

Chacko told reporters after Monday's examination of the former auditor that Singh was of the opinion that "to show presumptive loss in the 2G report is to bring in individual judgement which is questionable".