NEW DELHI: India’s anti-corruption mascot and Delhi Chief Minister Arvind Kejriwal said on Tuesday he has ordered criminal cases to be filed against billionaire Mukesh Ambani, Indian Oil Minister Veerappa Moily and other policy-makers for colluding to inflate the prices of gas.

In a rare assault in recent memory on India's powerful and politically connected business house, Mr Kejriwal said Reliance Industries Limited, owned by Mr Ambani, had been allowed windfall and illegitimate gains.

Mr Kejriwal's Aam Aadmi Party (AAP) had earlier accused Gujarat Chief Minister Narendra Modi of being a political face of the big business, singling out Mr Ambani and fellow businessman Gautam Adani as his supporters.

The chief minister said his move was prompted by a complaint his office received from former cabinet secretary T. S. R. Subramanian, former expenditure secretary E. A. S. Sarma, retired admiral R. H. Tahiliani and advocate Kamini Jaiswal.

A senior Anti-Corruption Bureau (ACB) official said FIR would be registered under IPC sections that will cover crimes such as anti-national activity, fraud, conspiracy and cheating and the Prevention of Corruption

Act. The Delhi government, the official added, had jurisdiction over the case. The Indian government in December said that from April 1, Reliance could double the prices of gas that it produces from the D6 block off India's eastern coast. Mr Kejriwal wants Prime Minister Manmohan Singh to suspend that hike pending an enquiry.

Reacting to Mr Kejriwal's charges, Oil Minister Veerappa Moily said: “Nothing is done without expert advice. If he can give (us) some money, we'll be happy to reduce prices.”

A statement from Reliance described Mr Kejriwal's decision as “shocking” and his charges as “completely without merit” and said it would resort to “available legal remedies”.

The chief minister said that the alleged swindle would unfairly push up gas prices in the capital, which was why his government was intervening in a deal struck between the centre and Reliance.

Reliance, which operates the D6 block off the eastern coast, has reported a sharp decline in gas output since 2010. It has blamed geological complexities for the fall in output, but the oil regulator believes it failed to drill enough wells.

The government cleared the higher prices after Reliance offered financial guarantees to the government to settle any claims against it over a shortfall in its gas output.

The D6 block was expected to contribute up to 25 per cent of the gas supply for Asia's third-largest economy but lower-than-expected output has left the energy-hungry nation more dependent on expensive, imported LNG to fuel power and fertiliser plants.