However, the timing of adding the bulk diesel price to the main wholesale price index (WPI) measure is not yet certain, they said.
India deregulated diesel prices by allowing fuel retailers to raise the price of subsidised diesel by 1 U.S. cent a litre every month and asking bulk buyers, who account for 40 percent of fuel consumption, to pay market rates.
The next headline data release, for January, will be made in mid-February.
"We have already initiated the process. It would be reflected in the WPI index as soon as we start getting the data" on dual pricing of diesel, a senior official at the Ministry of Commerce and Industry, who declined to be named because he was not authorised to speak on the matter, told Reuters.
"It may take two weeks, four weeks, or two months," he said, adding the ministry releases provisional monthly WPI inflation data and in case there was delay in getting the data, it may be reflected in final numbers released with a lag of two months.