New Delhi, Nov 17 (IANS): A special court Thursday issued notice to Central Bureau of Investigation (CBI) seeking its reply on a petition which alleges that the probe agency tampered with evidence in the second generation (2G) spectrum allocation case.

The direction came after all the 14 individuals accused in the case, including former telecom minister A. Raja, moved the application to prevent what they termed as an unhealthy practice of calling witnesses unofficially and tampering with evidence.

Issuing notice, the Special CBI Court, presided over by Judge O.P. Saini, asked the probe agency to file its response by Nov 23. The application by advocate Majid Memon was based on the deposition of Reliance Group executive A.N. Sethuraman.

In the application, Memon alleged that the CBI suspiciously and unauthorisedly invited Sethuraman, a witness, to its offices two days before trial was to begin. Such practice is not permissible in law, he submitted, and called for restraint.

The counsel also sought the court's direction to mobile service providers to preserve call detail records of the mobile number used by Sethuraman and the number from which he was called by a CBI officer to come to the agency's office Nov 9.

The Reliance Group official had told the CBI Special court Nov 16 that he was called two days before the trial was to begin. It was then for the first time that CBI showed him a copy of what was attributed as his statement, he said.

"I was not satisfied with contents of my statement and I protested to the officer to change the content thereof relating to identification of signatures of Hari Nair (also a Reliance Group official and an accused in the case)," he had said.

Sethuraman, in fact, told Judge Saini that CBI, instead of changing his statement as desired, even asked him to stick to whatever was shown to him.

Meanwhile, three of the accused in the case -- Raja's former personal secretary R.K. Chandolia, Swan Telecom's Shahid Balwa and Kusegaon's Asif Balwa -- moved a petition seeking alteration of charges framed against them Oct 22.