Official figures show the eurozone is in deflation as consumer prices fell in December due mainly to plunging energy costs.

Eurostat, the EU's statistics agency, says Wednesday that prices in what was then the 18-country eurozone were 0.2 percent lower in December than the previous year. The main reason behind the slide from the 0.3 percent inflation rate recorded in November was the plunging oil price, which is being passed on to consumers at the pump.

The decline was bigger than anticipated. The consensus in markets was for a 0.1 percent fall.

Confirmation that the eurozone is suffering deflation is likely to cement expectations that the European Central Bank will soon back an aggressive monetary stimulus similar to the one the U.S. Federal Reserve recently brought to an end.