The CBI has approached the Comptroller and Auditor General of India seeking its help in financial aspects of the probe into the 2G spectrum case.
"Investigation is still in progress and we have requested the CAG to help us in the probe into the case in terms of financial aspect and the audit," CBI Director Ashwani Kumar said today.
He said the Central Vigilance Commission has already conducted a probe into the matter and the CBI is also looking further into it.
Asked if the agency would question some other people including high-profile corporate lobbyist Neera Radia, who figured in a purported telephonic conversation with a Union minister over 2G spectrum allocation, Kumar said, "If it is relevant, we will look into it."
The CBI had registered a case on October 21, 2009 against unknown Department of Telecom officials and private persons and companies for allegedly causing loss of thousands of crores of rupees to the exchequer.
Ever since the 2G licences were issued last year, there has been allegation of irregularities.
The CBI has earlier searched offices of Wireless Planning Cell (WPC), the department responsible for allocating Spectrum, and the office of Deputy Director General (Access Services) of the Telecom Ministry to probe the allegations of connivance of officials with private companies in allocation of Spectrum.
It had also conducted searches in eight cities housing headquarters of various telecom firms in connection with its probe into the alleged scam.
The Enforcement Directorate has also registered a case under Prevention of Money Laundering Act in connection with the CBI case and is probing the overseas transactions of private firms and certain unknown officials.