New Delhi, Jan 3 (IANS): Prime Minister Manmohan Singh Friday said any wrongdoing with regard to 2G spectrum allocation and coal block allocations "will be punished" through due process of law.

"There is much public concern on high profile allegations of corruption, notably in regard to 2G spectrum allocations, coal block allocations and cases related to land," he said while addressing the media here.

"Where some decisions taken earlier, when allocations were made administratively, have come under question, they are being investigated. Any wrong doing will be punished through due process of law."

"We have taken major steps to change the existing procedures for allocation of spectrum and coal by shifting to auctions so that these problems do not arise in future," he added.

He said that he felt "somewhat sad" that he was the "one who insisted spectrum allocation should be transparent, fair".

The Comptroller and Auditor General report that was tabled in Parliament in November 2010 had put the presumptive loss from 2G spectrum allocation between Rs.57,666 crore and Rs.1.76 lakh crore.

He expressed hope that when history is written, "we (the UPA government) will come out unscathed".

"Opposition has vested interest and sometimes media plays into their hands as well," he added.