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.
Ex-Telecom Secretary Behuria and Raja's personal secretary P S Chandolia also arrested.
The CBI, earlier today questioned 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.
