New Delhi, Aug 17: In a fresh blow to India's multiple scam hit ruling United Progressive Alliance (UPA) government led by Congress Party, the auditor watchdog, Comptroller and Auditor General (CAG) on Friday submitted its report in the Parliament accusing the government of allocating coal blocks, power projects and land for Delhi's flagship airport at a fraction of market prices.

According to CAG estimates, government's decision caused losses to exchequer of around Rs 1.86 trillion ($33 billion) by allocating coal blocks to private players at sub-market prices, giving olive branch to opposition to demand resignation of PM Manmohan Singh.

Leading Opposition Party demanded PM's resignation saying that he was personally looking after the ministry between 2004 and 2008 in which period coal blocks were allocated resulting into coalgate scam.

"We want an explanation from the prime minister who was in charge of the Coal Ministry during the period of sale," BJP leader Rajiv Pratap Rudy told reporters after the report was released.

Shares in Reliance Power, India's second-largest power producer by market value, which has been named in the report along with Tata Power and Jindal, tumbled on Friday.

Going by the earlier stand of non-involvement in any wrongdoing, PMO said the government was simply following established policy.

"The report will not stand because it is not based on proper evidence," said V. Narayansamy, a junior minister in the prime minister's office.

CAG, in another report, said that airport land was allocated to GMR Infrastructure Ltd at a tenth of its market value, giving the developers an undue profit of $4.3 billion.

"The procedure followed for allocation of coal blocks to captive consumers lacked transparency as the allotments ... were made merely on the basis of recommendation from state governments and other administrative ministries without ensuring transparency and objectivity," CAG said in its report.

CAG report further said Reliance Power, controlled by billionaire Anil Ambani, gained Rs 290 billion in undue benefit from the government decision allowing the power producer to use surplus coal from its captive block for another project.

Scam hit Manmohan government, which recently reshuffled cabinet to boost growth; will have to struggle to get appropriate answer as in scam of similar relating to allocation of 2G spectrum apex court has cancelled licenses.

On the other hand anti-graft crusaders will have now new weapon in hand to challenge government on all possible front.