The way Jersey's Retail Price Index (RPI) is calculated is being investigated.
The inflation rate has fallen below 4% for the first time in two years
Senator Philip Ozouf, vice-president of the Finance and Economics Committee, is looking into concerns that recent figures were wrong.
The investigation comes after airlines disputed the latest statistics.
They showed airline fares have risen by about 26%, contributing to 1% to the island's overall inflation rate.
The figures led to suggestions that the airlines were not passing on the subsidies agreed by the Airport Task Force to keep fares down.
But airline Flybe said the figures were misleading because, in its case, they excluded internet sales of tickets.
Flybe said internet sales made up 81% of its total sales and its fares had actually gone down by 21% in the past year.
Deputy Lyndon Farnham said there has to have been a mistake.
He said: "It is simply unacceptable if there has been a miscalculation in the RPI."
"This has serious ramifications for the island."
Senator Ozouf said he is concerned as well and is investigating how the figures were calculated.
He said: "I want full details of how the figures were calculated, of the methodology they used, when the methodology was introduced, when it was last changed and what are they doing to change it."
"Independent statistics published without interference from politicians, compiled robustly, reviewed independently, are absolutely crucial to the workings of government and the workings of the island.
"We must have complete confidence in statistics provided by our statistics people."
Despite the concern of airlines adding to inflation, the overall island rate itself is below 4% - at 3.8% - for the first time in nearly two years.