The Central Bureau of Investigation on Thursday opposed the plea for setting up a committee of experts for effective monitoring of the probe in 2G spectrum scam case by claiming in the Supreme Court that "it has done fairly credible job".

"Untill this hearing, your lordship on each occasion and on looking into the status reports did not find anything wrong in our investigation," senior advocate K K Venugopal, appearing for CBI, told a bench of justices G S Singhvi and A K Ganguly.

He said a very high-profile case is under investigation and investigating officers are working day and night and a large number of persons from different spheres are assisting the probe.

CBI said no other organisation in the country has investigated the economic offence of such a high magnitude with such a speed.

"You are driving the agency to speed up the investigation and the results are coming. CBI is very independent in its work. We have not accepted the report of a ministry. We have not accepted the report of TRAI on zero loss. CBI is independent from the control of the government."

"The facts that a minister from coalition partner and the MP from the coalition partner and daughter of the then Chief Minister of Tamil Nadu has been arrested show the independent character of CBI requiring the probe not to be monitored by any other," Venugopal said opposing the plea for appointing two or more persons of eminence to monitor the probe.