The central bureau of investigation is set to question former communications and IT minister Dayanidhi Maran and others early next week in connection with the Maxis-Aircel deal as part of the 2G spectrum allocation scam, CBI sources said on Tuesday.

The agency is likely to tighten the noose around Dayanidhi Maran during whose regime the deal took place, his businessman brother Kalanidhi Maran and Maxis owner T Anand Krishnan.

The probe agency has received some crucial information related to the deal from the investigating agency of Malaysia, where Maxis is based, in reply to its letter rogatory sent earlier this year, the sources said, adding that a formal reply from the Malaysian agency is expected this week.

[A letter rogatory is a formal letter of request from a court to a foreign court, seeking judicial assistance, usually in the process of recording evidence.]

CBI needs help from its Malaysian counterpart to investigate the investments made by the Malaysia-based Maxis Communications in Aircel and later allegedly in the Marans-controlled Sun Television network. With the help of Malaysian authorities, the agency hopes to get details of the alleged role of the Maran brothers and Krishnan.

In February, the enforcement directorate also registered a money laundering case against the Maran brothers in the 2G spectrum scam.

In December 2006, the department of telecom (DoT) issued 14 licences to Maxis-controlled Aircel Communication. Maxis allegedly invested Rs 550 crore in Sun TV from 2007 to 2009, followed by another investment of Rs 111 crore in the media group owned by the Maran brothers, the sources said.

The CBI had searched the premises of the Maran brothers in October last year after registering a case against the Marans, Krishnan and Ralph Marshall of Maxis. It also named Sun TV and Maxis in the first information report (FIR).