New Delhi, Nov 19 (IANS): A Delhi court hearing the 2G spectrum case was Tuesday informed by the chief investigating officer (CIO) that he was not aware about lobbying by former corporate lobbyist Niira Radia with the department of telecom and other departments for the Tatas.

Testifying as a prosecution witness in the case, Central Bureau of Investigation (CBI) Superintendent Vivek Priyadarshi said he received the recorded telephonic conversations of Radia from the Income Tax department during the probe into the case.

"It was not in my knowledge that Niira Radia used to do lobbying with the department of telecom and other departments in favour of the Tatas by making them abuse their official position. The conversation of Niira Radia was obtained by me on a sealed portable hard disc from the Income Tax department," he told Special CBI Judge O.P. Saini.

During cross examination by defence counsel, Priyadarshi rejected the submission that he had "pressurised" R.K. Chandolia, the then private secretary to A. Raja, to make a statement against the former telecom minister regarding matters about which he had no knowledge.

He denied that Aseervatham Achary, Raja's former additional private secretary and a key CBI witness in the case, was used by him to make a statement in favour of CBI.

Raja and many others, including DMK MP Kanimozhi, are facing trial in the case.