NDTV Correspondent, Updated: July 18, 2011 18:14 IST.
The CBI said it wanted to question the trio before it filing its next supplementary chargesheet in the 2G spectrum scam.
Sources say the entire questioning was focused on the Loop-Essar nexus.
Sources also say that the CBI in its third chargesheet will mainly focus on these companies. The investigation agency believes Loop was a front for Essar and is now trying to gather all possible evidence to corroborate that.
The reason Mr Doshi was questioned along with Mr Raja and Mr Behura is because the CBI wanted to know if he was aware of other telecom companies like Loop devising strategies to circumvent the rules and whether Raja and his men helped them in the process, sources add.