New Delhi: The Supreme Court on Thursday ordered the CBI to probe the restoration of 2G spectrum licence to Chennai-based telecom operator S-Tel after its licence was cancelled on grounds of threat to national security.

The Apex Court also asked the agency to investigate the antecedents of the UAE-based Etisalat. The Home Ministry had earlier expressed reservations to the Department of Telecommunication and the Union Finance Ministry regarding the foreign direct investment made by Etisalat in the telecom sector.

A bench of Justices G S Singhvi and AG Ganguly asked CBI to apprise the court of their findings on March 15.

Senior CBI advocate KK Venugopal, however, said as the issues concerning the two firms did not directly relate to the 2G spectrum allocation, the agency may take some more time to complete the probe.

Meanwhile, Attorney General Goolam E Vahanvati, explained to the bench about the telecom policy adopted since 1994 and said the spectrum was allocated on the basis of the policy decision which does not envisage its allocation by auction.

Vahanvati said that a joint parliamentary committee and the Public Accounts Committee too were looking into the issue of the spectrum allocation and were also examining the CAG report on it.

The Attorney General added that the matter was also being probed by the CBI on the direction of the Apex Court, which is also monitoring the investigation.