New Delhi: Noted lawyer Shanti Bhushan, who is also a member of the Lokpal Bill drafting committee, has filed a contempt petition against former Samajwadi Party general secretary Amar Singh in the Supreme Court over the controversial CD that allegedly showed him (Bhushan) talking to Mulayam Singh Yadav and Amar Singh about fixing a judge for Rs 4 crore.In the petition filed on Monday, Shanti Bhushan has also sought the formation of Special Investigation Team to investigation who else are reportedly involved in production and distribution of the CD.Earlier, Singh threatened to file a defamation suit against Shanti Bhushan’s son Prashant Bhushan for reportedly saying he was behind the anti-Bhushan CD that has now been found to be doctored. He also claimed that Bhushan has committed contempt of court by reading out transcripts of his phone tap of 2006."Since my taped conversation is illegal as said by (Attorney General) Goolam Vahanvati in court and the law officer also said that the letter given to Reliance Infocom for tapping my phone and the signature of the police commissioner was forged. Despite that excerpt of that tape was read by Prashant Bhushan. I will tell him 'papa don't preach'. It shows the illegality and he played it so it's a case of contempt of court. I am going to file a defamation case against Prashant Bhushan and Swami Agnivesh for naming me," said Singh.Singh also lodged a complaint with the Delhi Police against charges levelled by Prashant Bhushan. He also gave a set of CDs to the police claiming that the CD that has come in public domain were the original one.He has alleged that the CD released by Prashant Bhushan and Shanti Bhushan was the fabricated one. He will also lodge a complaint with the Registrar General of the Supreme Court.Prashant Bhushan claimed that his father had filed an FIR as soon as he got to know about the CD."As soon as the CD was brought to our notice my father lodged an FIR in relevant police station saying he's never ever spoke to Amar Singh or had tripartite conversation with these people. The CD is fabricated and police is investigating the matter," he said.Union Home Minister P Chidambaram said that the Delhi police would consult at least two forensic labs to verify the audio and the authenticity of the CD."This is a season of allegations and I am glad that there is a growing recognition that reputations are also important. I have been assured by Delhi Police that free, fair and thorough investigations will happen into the Shanti Bhushan CD case," said Chidambaram.The Samajwadi Party has also given a clean chit to Shanti Bhushan, saying he never had the conversation with Mulayam Singh Yadav.