CBI on Wednesday questioned former telecom minister A Raja for the fourth time in connection with the funding and allegedly showing favours to some telecom companies in granting 2G spectrum between October 2007 and 2008.
Raja, who was questioned earlier on December 24 and 25 last year and January 31, was called to the CBI office on Wednesday morning and quizzed, official sources said.
The DMK MP would be confronted with some questions and documents recovered from the computers seized during raids conducted by the investigation agency earlier at his premises.
Raja was on earlier occasions questioned at length on the circumstances leading to spectrum allocation which has been criticised severely by the Central Vigilance Commission and the Comptroller and Auditor General (CAG).
He was also asked about his conversations with corporate lobbyist Niira Radia and the reasons of advancing the cut-off date of allocation of the spectrum in 2007.
Raja was forced to resign on November 14 last year in the wake of the CAG report which held that the spectrum allocation at undervalued prices resulted in a notional loss of Rs 1.76 lakh crore to the state exchequer.
Raja got the telecom portfolio on May 18, 2007 and was re-elected as a Member of the 15th Lok Sabha and continued as telecom minister from May 31, 2009, till November 14, 2010 before he tendered his resignation.
The Supreme Court has asked CBI and Enforcement Directorate to submit status reports on their investigations into the 2G spectrum case to it by February 10 when the case will come up for further hearing.
In its FIR, CBI mentioned the loss as Rs 22,000 crore based on CVC findings which had referred the case to it.
Radia was quizzed by CBI last week as she had come under the scanner after her tapped telephonic conversations with various influential people including industrialists, politicians and journalists became public.
CBI has also questioned former Telecom Regulatory Authority of India (TRAI) chief Pradip Baijal, a 1966 batch IAS officer of Madhya Pradesh cadre, and former telecom secretaries Siddarth Behura and D S Mathur in connection with the case.