The Lok Sabha panel probing the cash-for-vote scam is finding it difficult to nab culprits behind the scene as none of them figure in the tapes of the sting operation it examined on Monday.

Coverage: The UPA Trust Vote

All indications so far are that Samajwadi Party leader Amar Singh [Images] -- accused of buying the MPs -- may go scot-free.

Circumstantial evidences based on the statements of the three BJP lawmakers were felt insufficient to summon Amar Singh and Congress President's political secretary Ahmed Patel, sources privy to the panel's sittings disclosed.

Sources said the panel will not summon Amar Singh and Ahmed Patel who are Rajya Sabha members, as seen from the time-table it has fixed for the inquiry, more so because it is not sure if it can summon members of the other House.

The panel has, however, summoned Sanjeev Saxena, the alleged courier of Rs 1 crore for delivery to the BJP lawmakers, on August 18. Also summoned that day is Samajwadi Party lawmaker Reoti Raman Singh, who had gone to the residence of BJP lawmaker Ashok Argal to persuade him and another MP from Madhya Pradesh [Images] to meet Amar Singh.

Sources said the sting operation tapes of television channel CNN-IBN, viewed by panel members, do not show Reoti Raman Singh uttering the name of Amar Singh even once. He is heard suggesting them Miliye to sahi unse (At least meet him), which does not show he brokering on behalf of Amar Singh, the sources said.

Even Saxena, seen telephoning purportedly to Amar Singh from the residence of Argal after delivering the money cannot establish anything beyond the fact that he rang up Amar Singh's residence as it does not prove whether he spoke to the Samajwadi Party leader or someone else, the sources said.

They pointed out that the additional evidence furnished by two of the complainant BJP lawmakers that include audio tapes and their transcript, can establish that Saxena was working with Amar Singh, but the latter has already torpedoed that evidence too.

Amar Singh has already found the alibi by claiming in a press conference on Monday that Saxena had already defected on July 20, two days before the alleged delivery of money to the MPs to abstain from voting, along with Samajwadi Party MP Shahid Siddiqui [Images].

All the evidence that BJP general secretary Arun Jaitley has dug out to show Saxena's link with Amar Singh, including the address of the latter he gave in application of his son for college admission, falls flat in the face of Amar Singh claiming that he had left the Samajwadi Party on July 20.

The car by which Saxena is supposed to have reached Argal's residence to deliver the money can be linked with Amar Singh, but here too the latter would have the alibi that Saxena did not return the vehicle while defecting with Siddiqui.

While the three complainant BJP MPs -- Ashok Argal, Faggan Singh Kulaste and Mahavir Bhagora -- who flashed the money in Lok Sabha as the bribe to abstain from voting that stunned the nation, have been called by the panel for deposition on August 7, the CNN-IBN team that conducted the sting operation has been called on August 11.

After recording evidence of Saxena and Reoti Raman Singh, the panel would sit down to hold its own meetings to sum up conclusions and send the report to the Speaker. The tentative date fixed for submitting the report is August 25, sources said.