The UK’s inflation rate, as measured by the Consumer Prices Index, fell to 2% in December, down from 2.1% the month before.
It is the first time inflation has been at or below the government-set target of 2% since November 2009.
The Office for National Statistics said the fall was caused by slower increases in the prices of food.
Inflation as measured by the Retail Prices Index (RPI) rose to 2.7% from 2.6% in November.
The ONS said the rise in prices of both food and non-alcoholic drinks was the smallest it had been since 2006.
Phil Gooding from the ONS told the BBC that a slowdown in the increase of fruit prices, particularly bananas and grapes, as well as meat prices helped to drive the fall in the inflation rate.