A committee set up by the finance ministry has said that some of the conversations of Niira Radia, which have been brought into the public domain by magazines such as Outlook and Open, are not in the records of the Income Tax Department.

The revelation could open a new can of worms because of the underlying implication that there might have been an unauthorised tapping of Radia's phones by a service provider or another agency.

The report, contents of which were described to ET reporters, says the I-T department did not leak the telephonic interceptions relating to Radia. On the contrary, the two-member committee has stated that "available evidence suggests that the leakage may be from a source different from the Income Tax Department".

The reason for this conclusion, as spelt by the committee, is that the time stamps on common call records available in the public domain, such as the magazine websites and in the server of the I-T department are different, implying that since the two sets of call recordings are different, more than one agency or entity may have been involved in the phone-tapping.

The report also says that some of the call recordings available in the public domain are not available in the records of the I-T department, implying that the recordings that have become public have also been sourced from elsewhere. The committee has also said that a further inquiry is needed to "establish the leakage of the intercepts by the telecom service provider to identify the actual individuals who are involved in this".

The report did not name the service provider.

A spokesperson for Radia declined comment on the matter. "We have complete faith in the due investigative process on the unfortunate episode relating to leaks of purported telephonic conversations involving our colleagues. We will not be able to offer any comment on reports that are not in public domain and hence not privy to us. However, we wish to reiterate that there was an attempt to create a smokescreen by certain vested interests to divert attention from their own wrongdoings," the spokesperson said.

But not everyone is convinced by the findings of the revenue department committee. "CBDT comes under the Department of Revenue. This committee had representatives from the tax department. So, the conclusions are hardly a surprise," says the head of another government investigating agency who did not wish to be identified given the sensitivity of the matter.

"A leak of this kind has rarely happened from any agency authorised to tap phones. The rules as laid down for interceptions also provide that recordings be destroyed if no action is taken within six months. Why did the I-T department not do the same for these recordings, more so when it hasn't taken any action on the Radia matter," he added.

The head of another government investigative agency also concurs with this view. "The tapes could have been leaked out from nowhere except the I-T department. How can this probe be taken seriously since it has been conducted by the department where the leak happened," he says.

Radia's phones had been put under interception for several months by the Income Tax department in 2008 and 2009. Subsequently her conversations with an array of businessmen, journalists and politicians, including ousted telecom minister A Raja, surfaced in the public domain late last year leading to media frenzy.

The Radia tapes , as the conversations are known as, revealed that she lobbied to get Raja reinstated as the telecom minister when the UPA government came back to power in May 2009.

Shortly after the conversations were made public, Tata Group chairman Ratan Tata moved the Supreme Court, seeking action against those responsible for the leakage of his tapped conversation with Radia. In his petition, which had made the central government a party, Tata argued that leakage of the tapes had infringed upon his rights to privacy.

After Tata's petition in the Supreme Court, the finance ministry set up a two-member committee to probe the leak. Not many people within the government were convinced about the committee's ability to carry out an objective or a fair probe because of the fact that it had representatives from the tax department. CBDT chairman Sudhir Chandra did not respond to calls or SMSes sent to his mobile phone.

Revenue secretary Sunil Mitra did not respond to a detailed email questionnaire sent to him last Wednesday. Mitra did not confirm to ET whether the finance ministry had accepted the report of the two-member committee or whether it had been submitted to the apex court.

The two-member committee has, however, conceded that there has been some leak of "classified documents" from the record of DGIT, New Delhi , but it said it was unable to conclude as to how the documents leaked or who was responsible for the leak.

A few months back, a document had been circulated in Delhi's government and media circles which blamed senior I-T officials for the leak. The document, which was unsigned, alleged that the leak was the responsibility of a top I-T official. The source of the document was unknown. Some officials in the finance ministry had blamed officials in the home ministry for circulating the unsigned note. The I-T officials in turn, had alleged, that the leak happened by the Intelligence Bureau at the behest of the home ministry.

The matter was also taken up by finance minister Pranab Mukherjee with prime minister Manmohan Singh . But an affidavit filed in the SC earlier by the government clearly stated that only the I-T department had tapped Radia's phones and the tapes were shared only with the Central Bureau of Investigation.

The government has set up a 15-member inter-ministerial group to suggest measures to prevent such instances. The group, led by the home secretary, will frame norms for the use of tapped conversations and destruction of non-relevant information, which are private in nature and have nothing to do with any investigation.