The CBI on Tuesday opposed in the supreme court a plea for probing home minister P Chidambaram's alleged role in the 2G spectrum scam case saying it is beyond its jurisdiction to entertain it.

Maintaining that the probe into the multi-crore scam during the tenure of former telecom minister A Raja was complete, the agency opposed the plea of Janata Party President Subramanium Swamy.

Swamy sought the probe alleging that Chidambaram, the then finance minister, was party to conspiracy with Raja in deciding the price for spectrum.

At the outset, both the CBI and the Centre questioned the maintainability of Swamy's plea saying he has filed a similar application in the trial court and the issue has to be decided by the special CBI Court.

The CBI said that supreme court cannot give such an order and it for the trial court to take decision on the issue.

"Questions of any further investigation or addition of accused in the case have to be decided by the trial court and not by this court," senior advocate K K Venugopal, appearing for the CBI, submitted before a bench of Justices G S Singhvi and A K Ganguly.

"Investigation is complete in 2G scam (during the tenure of Raja) and framing of charges is to be decided by the trial court. If the trial court finds that there is any wrong doer then it can add the person in the list of accused," he said questioning the jurisdiction of the apex court to entertain Swamy's plea.

"Magistrate has exclusive jurisdiction in the case," Venugopal said adding that once the investigation in a case is complete then it comes within the jurisdiction of the trial court and beyond the purview of the court monitoring the probe.

"The case is not a narrow one and it has a huge ramification," Venugopal said adding that "Swamy is riding two horses at the same time".

Swamy's plea was also opposed by the Centre, which said with the cognisance taken by the trial court, the issue exclusively falls in its jurisdiction.

"Trial court has exclusive jurisdiction to take cognisance and hear the matter and once the cognizance has been taken, it is the exclusive jurisdiction of the special court," senior advocate P P Rao, appearing for the Centre, submitted.

Venugopal said "every single document, filed in the supreme court, has also been placed before the trial court. He cannot ride two horses at the same time and that is what he is doing right now."

"Let him go and pursue the matter there in the trial court," the senior advocate said.

Swamy, however, refuted the allegation saying that his application before the apex court was different from that which was filed in the special court.

He alleged that the CBI was determined to give a clean chit to Chidambaram who met with Raja four times between January 2008 and July 2008 on the issue of fixing the price of spectrum.

"CBI seems to be determined to give a clean chit to the then finance minister, who is now the home minister," Swamy said.