A four-member team of the Central Bureau of Investigation on Saturday questioned the former Chief Executive Officers of Sun TV and Kalaignar TV, Hans Raj Saxena and Sharad Kumar, in a case relating to an illegal telephone exchange that functioned at the Chennai residence of the former Telecom Minister, Dayanidhi Maran.

The CBI began the investigation in 2011, nearly four years after complaints that Mr. Maran, during his tenure as Telecom Minister, had the exchange with 323 high-speed lines connected to his Boat Club residence.

While the CBI confirmed that Mr. Kumar and Mr. Saxena were summoned by a team that camped in Chennai, CBI spokesperson Kanchan Prasad said the two were questioned.

A senior CBI official said: “Since it is alleged that the exchange, installed at Mr. Maran’s residence in 2007, was used by Sun TV to uplink programmes, we are examining the then senior functionaries to document their versions and ascertain in what ways the 323 Integrated Services Digital Network (ISDN) BSNL lines were put to use.”

Top CBI sources told The Hindu that some crucial BSNL documents pertaining to the installation of the ISDN lines had gone missing.

“We are trying to locate those papers. Besides, BSNL is extending to us all technical assistance to calculate the number of international calls made, and the consequent loss to the exchequer,” said a source.

More In: Tamil Nadu | National