JOIN USOfficial sources said Raja's brother A K Perumal came to the CBI headquarters here in the morning and his questioning took place till late in the evening.
Sources said the agency is in the process of questioning everyone whose premises were searched by it in connection with the investigations into the scam.
The agency had questioned Raja yesterday for over eight hours.
Though officials were tight-lipped about the line of questioning, sources said, he was questioned on certain financial transactions and his dealings with certain firms.
CBI had yesterday questioned former Union minister A Raja for the third time in connection with the funding and allegedly showing favours to some telecom companies in granting 2G spectrum between October 2007 and 2008.
Sources said another associate of Raja was also questioned today in the same case.