New Delhi: The CBI has completed its probe in the 2G spectrum allocation scam and will file its third chargesheet by September 15, the agency told the Supreme Court on Wednesday.

Senior Advocate K K Venugopal, appearing for CBI, sought 15 days more to file the chargesheet which was earlier slated to be filed by August 31.

He submitted before a bench of Justices G S Singhvi and A K Ganguly that the CBI, Enforcement Directorate and Income Tax department would file status report of their investigation by the next date of hearing on September 1.

Earlier in the day, jailed former Telecom Minister A Raja told a Delhi court that he would get Prime Minister Manmohan Singh, then Finance Minister P Chidambaram and present Telecom Minister Kapil Sibal summoned as witnesses to prove government did not incur any loss in the 2G allocation.

"Aaj main bata dena chahta hu ki main Prime Minister, tabke Finance Minister or vartman ke Telecom Minister ko battor gawah banaunga (I want to state that I would get the Prime Minister, the then Finance Minister and the present Telecom Minister summoned as witnesses)," Senior Advocate Sushil Kumar, appearing for Raja, told Special CBI Judge O P Saini.

The moment it is established that there was no loss to the state exchequer, the whole case of cheating and conspiracy in the spectrum allocation will go, he said, claiming that the Prime Minister and two other ministers would be able to establish that.

He said Raja would move an application under section 91 of the CrPC for getting certain documents from the CBI which had so far not been brought before the court.

The defence counsel also raised the issue of offloading of equity by Swan Telecom Pvt Ltd and Unitech (Tamil Nadu) Wireless Pvt Ltd to Dubai-based Etisalat and Norway-based Telenor respectively and maintained that there was no criminality involved in those transactions.

"First of all there was no sale of licences, then the offloading of equities was within the limit of 74 per cent. Moreover, the transactions were cleared at the highest level (the Foreign Investment Promotion Board)," he said.

Earlier, Telecom Minister Kapil Sibal had also asserted there was "zero loss" to the exchequer.

Trai's statement came in response to a CBI request to fix the losses suffered in the award of licences, as several figures were doing rounds. The Comptroller and Auditor General had pegged the loss between Rs 57,000 crore and Rs 1.76 lakh crore, depending on the method used for calculation.

The CBI had earlier projected the loss at around Rs 22,000 crore. However, it increased the figure to Rs 30,000 crore in its first chargesheet in the case.

The agency wanted the regulator to set up a team of experts for a definitive calculation of the losses arising out of the allocation of licences during the 2001-08 period, which could stand up to legal scrutiny in court.

However, the Trai advice buttresses the points put forth by Raja, Behura and other accused in the case that there was no loss suffered by the exchequer in the award of 122 licences to telecom companies at 2001 prices.