Petrol is over 20% more expensive in Italy than it was a year ago, Istat said on Monday when releasing figures that look set to feed public anger about fuel prices.
The national statistics agency said petrol prices were 20.9% higher in April with respect to the same month in 2011, the biggest year-on-year increase since May 1983.
Consumer groups have accused petrol companies and distributors of unfairly jacking up prices over the last year, with prices approaching two euros a litre.
Several companies cut their prices by up to two euro cents last week after the government made a "firm" call for them to bring their prices into line with the European average.
Istat confirmed its provisional forecasts for the overall rate of inflation, which it said remained steady at 3.3% in April.
But the index for the 'trolley' of most-frequently bought goods by consumers was up by 4.7%, its biggest increase since September 2008.