A CBI team on Friday visited office of oil regulator V K Sibal to check records following charges of his receiving favours from Mukesh Ambani-led RIL to approve an inflated expenditure for gas field, a charge denied by him.

The CBI was "looking into" the reference sent by the Central Vigilance Commission (CVC) for probing allegations that Sibal, Director General of Hydrocarbons, and his family received favours from Reliance Industries for approving a four-fold increase in capital expenditure for KG-D6 fields.

While RIL has refuted allegation of "gold-plating" of cost, Anil Ambani Group had alleged a connivance between Sibal and RIL and demanded a CVC probe.

When contacted CBI spokesman Harsh Bahal refused to comment saying the agency would not share any details. Sibal could not be reached for comments despite several messages.