The Supreme Court today expressed displeasure over the tardy pace of probe by the income tax department into the tax evasion cases linked to 2G spectrum case, saying it wanted "results".

A bench of justices G S Singhvi and A K Ganguly directed the department to file a detailed report on action taken by it during the last three years when it got a complaint in this regard and began tapping corporate lobbyist Niira Radia's telephone.

"The IT department must be quicker. This is not a normal case of tax evasion. It (probe) should have been done fast. These are not ordinary cases to be handled in ordinary way," the bench said.

The department, however, defended its ongoing probe saying that the investigation has entered the "fifth layer" and the approach towards the case has not been tardy.

The court, however, was not satisfied and said, "We are not concerned about layers but results."

The bench allowed the IT department to approach the special judge, trying the 2G case, to interrogate company officials who are in judicial custody for their alleged role in the scam. .