The family of slain former ISI official Khalid Khwaja, who was kidnapped and killed by militants in Pakistan's tribal belt, has said it will get a murder case registered against popular television anchor Hamid Mir.
Mir has been at the centre of a controversy since a purported telephone conversation between him and a Taliban operative was posted on several websites.
The Daily Times newspaper, which first reported on the tape, has said that information passed on by Mir to the Taliban "could have led to the execution" of Khwaja.
Osama Khalid, the son of the slain former Inter-Services Intelligence official said: "We are going to the police and the Supreme Court in a few days to get a case registered against Mir as he was instrumental in the murder of my father by the Punjabi Taliban."
He added: "The person who was conversing with Mir on phone about my father was Usman Punjabi alias Umer. I recognise his voice as he (Usman) had spoken to me on five or six occasions when my father was being held by the militants.
A hitherto unheard of group called the Asian Tigers claimed responsibility for the abduction and killing of Khwaja. It said Khwaja was killed as he had admitted to working as a spy for the US and the Pakistani military establishment.
Reports have suggested that Usman Punjabi is the head of the Asian Tigers.
In the recording, Mir is heard accusing Khwaja of being a double agent working for the CIA and of having played a "dirty" role in the 2007 military operation against radical elements holed up in the Lal Masjid in Islamabad.
"I have with me the call record (of the conversation between Mir and Usman Punjabi). The call was made on April 19 and the video of my father's confessional statement was released to the media on April 23. That is enough evidence to lay hands on this so-called journalist for his role in the killing of my father," Osama said.
Khwaja was kidnapped with another ISI official Sultan Amir Tarar alias Col Imam and British journalist of Pakistani origin Asad Qureishi on March 26 while en route to Waziristan ostensibly to make a documentary on Taliban.
Khwaja was shot dead on April 30 while the two other men are still in the custody of the Asian Tigers.
Osama further said: "The mistake my father committed was that he had told Mir that he was heading to Waziristan on a peace mission. Mir disclosed this to his friends there.
"The whole family is in shock as to how Mir could do this to my father," he said.
Osama urged Pakistan's Chief Justice Iftikhar Chaudhry to order a judicial inquiry to "find out the truth".