The demand followed a letter written by Rajya Sabha MP of Shiv Sena, Mukesh Patel, to the prime minister and the standing committee members, charging the company with resorting to various alleged malpractices to avoid payment of duties as well as being a party to theft of petroleum products and their resale through various front companies.

A RIL spokesman when contacted strongly refuted the allegations saying they were totally baseless. ``We do not know why the MP has chosen to make such unsubstantiated allegations,'' the spokesman said.

Committee chairman Balram Jakhar delcined to comment when asked if the issue of adulterated products was discussed by the members. However, he acknowledged to newsmen today that there was need for instituting measures to curbadulteration.

The MP had, in a two-page letter to the prime minister, said, ``I am pained to see a statement by Gujarat civil supplies minister expressing helpless to tackle the problem of petroleum adulteration due to pressures from various political and other quarters.''

Patel also quoted a Tata survey which indicated a loss of Rs 60,000 crore due to the adulteration in diesel alone.

In his letter, he gave details of how the `organised racket' is conducted by RIL pointing out instances of naptha operation at Hazira complex.

At the Hazira cracker plant, 2 million tonnes of naptha is imported by RIL as a `consumer', out of which only half is used to take out 300,000 tonnes of required chemicals, he said.

``The remaining is nothing but gasoline (petrol). Instead of selling this as petrol, they sell it as a by-product by paying only 10 per cent excise duty as against 164.5 per cent excise duty on petrol,'' Patel said.

``Needless to say, all these products are used for adulterating petrol while theremaining extra 1 million tonne of imported naptha is straightway sold under fake names to petrol pumps though front companies. ``The operation is costing the exchequer an amount of Rs 1,600 crore annully and also violates Fera regulation,'' he said.

He further alleged that Reliance had got into crude oil production in Panna Mukta through manipulative bidding. ``I believe that the CBI has already conducted an inquiry, but the inquiry reports have been suppressed at the ministry level at the insistence of the interested parties,'' Patel said.