Taking serious note of its inconsistent stand on Dayanidhi Maran’s role in Aircel case, the Supreme Court on Wednesday asked the NGO Telecom Watchdog to explain why it has given clean chit to the former telecom minister.

The NGO has been demanding a CBI enquiry into Dayanidhi Maran''s role in the alleged coercive transfer of Sivashankaran's stake in Aircel to Malaysia-based Maxis group and post-transfer showering of official favours followed by the foreign entity's quid pro quo.

Taking U-turn recently the NGO has written a letter to the CBI giving clean to Maran saying that there was no evidence to prove that he coerced the businessman into selling his stake in Aircel to Malaysia-based Maxis Group in 2006.

He even accused the businessman of cooking up a story against the former minister to extort money from Maxis.

The CBI started probe in to the matter following the allegations made by two NGOs, Telecom Watchdog and Centre for Public Interest and Litigation, before the SC in the 2G scam case.

A special bench of Justice GS Singhvi and Justice KS Radhakrishnan directed Kumar to file an affidavit detailing reasons for the U-turn. The CBI counsel KK Venugopal informed the court about the letter. Kumar apparently also wrote an article in a magazine, giving clean chit to Maran.

"After going through the contents of the letter written to the CBI, secretary of the Telecom Watchdog Kumar is directed to show as to under what circumstance he wrote a letter dated February 5, 2012 virtually exonerating Maran and accusing Sivasankaran within seven days," the bench said.