The Central Bureau of Investigation (CBI) has accused V K Sibal of colluding with private parties during his term as oil regulator and has sought government permission for a thorough investigation.
CBI, which was asked by the Central Vigilance Commission (CVC) to do a "discreet" ground verification of allegations of Sibal's nexus with private oil and gas operators, in its preliminary report, alleged "gross abuse and misuse of public office by Sibal", sources in the know said.
The preliminary report also talked of his "nexus with private parties" and his "obtaining pecuniary advantage in award of contracts and supply of information of sensitive data of resources".
However, neither the CVC nor the CBI have said anything on the allegations of his seeking favours from Reliance Industries (RIL) in lieu of approving higher capital expenditure at Mukesh Ambani-run firm's Krishna Godavari basin gas field.
CVC, last month, sought CBI help when its clearance was sought for giving an extension of service to Sibal as Director General of Directorate General of Hydrocarbons (DGH).
Sibal's term at the DGH ended on October 31.
Sources said the anti-corruption body's report stated that prima facie a "vigilance angle" has been established in certain cases of extension of contracts by Sibal. Also, the process followed in levying liquidated damages on companies for not fulfilling exploration commitments was found arbitrary and so was the award of contracts for speculative surveys.