An early Easter and lower air fares also helped drive down inflation from 2.8 per cent in March. It is the first drop since September 2012.
Economists had expected the consumer price index to fall by a more modest 0.1 or 0.2 per cent.
The only notable upward contributions came from food and non-alcoholic drink prices.
Inflation on the new CPIH index – which takes into account owner and occupier housing costs – grew by 2.2 per cent in the year to April 2013, down from 2.6 per cent in March.
The decrease in inflation will come as welcome news for individuals, easing household finance pressures and slowing the rate of erosion on savings pots.