A top executive of the Maxis group was on Monday questioned by the CBI in connection with alleged irregularities in spectrum allotment during the tenure of former Telecom Minister Dayanidhi Maran.

Ralph Marshall, CEO of Astro which invested in Sun TV and also a Board member of Malaysia-based Maxis, appeared before the agency officials for clarifying on allegations that the company was favoured by the Minister in the takeover of Aircel and in return investments were made in Sun TV owned by Maran family.

Sources in the agency said that Dayanidhi Maran may soon be questioned in the matter.

The CBI in its recent status report to the Supreme Court had said that during Maran''s tenure there was "deliberate delay" to provide letter of intent to the promotor of Aircel.

The agency had said after Aircel was sold to the Maxis Group, investments were made by the Malaysian firm into the family business of Marans.

Former aides of ex-Telecom Minister Dayanidhi Maran had reportedly told CBI that the processing of the files of former Aircel chief owner C Sivasankaran was delayed allegedly at the direction of the minister, sources in the agency claimed.

They had also told that Ralph Marshall had held a number of meetings with the telecom minister in office between 2005 and 06 on two to three occasions, the sources claimed.

Sivasankaran had alleged that his applications for licences were rejected when Maran was the telecom minister in 2006, forcing him to sell his company to Maxis, whose owner is considered to be close to Maran and his brother Kalanidhi, who owns Sun TV.

Later, Maran is alleged to have granted 14 licences to Dishnet Wireless (Aircel) during his tenure as the telecom minister.

The allegations have been refuted by Dayanidhi Maran. The CBI is looking into investments of Maxis in Sun TV which are alleged to have been done with Astro group.

Besides, it is also looking into various aspects of takeover of Aircel by Maxis group, agency sources said.

The probe agency has already registered a preliminary inquiry on issues in 2G spectrum allocation between 2001-07 and is actively looking into the matter.

The preliminary inquiry was registered against "unknown persons" following a Supreme Court directive to detect any alleged anomaly in 'first-come-first-serve' during the spectrum allocation between 2001-07.

Maxis has 74% stake in Aircel which has presence in 23 telecom circles.