The CBI on Wednesday summoned 2G scam accused Shahid Balwa for questioning with regards to audio recordings of purported conversation between its prosecutor A K Singh and another accused Unitech managing director Sanjay Chandra on the case.
Agency sources said Swan and DB Realty promoter Balwa was asked to join investigations in the case as his name cropped up in the purported conversation.
The agency is expecting more such conversations to emerge as it strongly believes that the recording and subsequent leakage of these conversations is the result of corporate rivalry in the telecom sector, they said.
Meanwhile, the agency has received the report from Central Forensic Science Laboratory (CFSL) about the previous CD, having conversations between its prosecutor A K Singh and Chandra, who is an accused in the 2G telecom spectrum allocation scam.
The CFSL in its report has said that the conversations are "untampered".
However, in the absence of any voice samples of Singh and Chandra, it could not authenticate whether the voices in the recordings are of the duo, they said. They clarified that so far there are no indications of CBI's case getting affected in the 2G scam.
Singh, who was removed after surfacing of tapes, has reportedly told investigators that there was nothing unusual in discussing case related facts with the defence and it is a normal practice as far as it does not adversely affect prosecution's case, they claimed.
Unitech had rejected the allegations, saying Chandra had never met the prosecutor in the 2G case outside the court or had any phone conversation with him.
The company has also denied that Chandra's voice was on the tape and said it appeared a fabricated voice recording sent anonymously to CBI.