The apex court was informed by CBI counsel and senior advocate K K Venugopal that the 
agency will take two months to complete the investigation and in another one month, it will arrive at a conclusion and file the chargesheet. DMK leader A Raja had resigned as Telecom Minister earlier this month in the wake of the spectrum scam.
"We are investigating the offences and for each charge there has to be evidence and documents. The CAG report is about financial impropriety and not a criminal act," Venugopal told a bench of justice G S Singhvi and A K Ganguly, adding that only after the probe it could be said whether "we have done our work properly or not."
He said that the CBI will take two months time to finish the investigation as it was examining transcripts relating to 5,000 calls (out of which 3,800 have been analysed), 6,000 files and 80,000 pages of documents.
All these are being scrutinized, the senior advocate, who is representing the CBI from today, said.
He further said since the matter was being examined by the CBI, the apex court should not go into the merits of the case.