He was questioned for nearly six hours today by the sleuths of CBI's Special Task Force during which he was confronted with the papers collected by the agency, official sources said.
He was quizzed yesterday for over seven hours and for eight hours the day before.
Before entering the CBI headquarters, Maran said that he was hopeful that CBI will take into account the documents submitted by him. He was Telecom Minister from 2004-07.
Maran had already been questioned in connection with the case in January and October last year, while his brother Kalanithi was quizzed once in September last year.
More From This Section
It is alleged that a loss of over Rs 1.8 crore was caused to the exchequer by use of such large number of high-capacity ISDN lines at Maran's Boat House Road residence in Chennai.
The residence was allegedly turned into a "virtual telephone exchange" to facilitate speedy transmission of programmes by Sun TV owned by Maran's brother Kalanithi.
The questioning comes at a time when Information and Broadcasting Minister Arun Jaitley was pushing for giving security clearance to Sun TV, which has been rejected by the Union Home Ministry.