Deflation across the 19 countries that use the eurozone currency is gathering pace.
In January, prices in the eurozone were 0.6% down on their levels a year ago.
The figure shows the eurozone heading deeper into deflationary territory from December, when prices were 0.2% down on the year before.
A large contributor to falling prices is the cost of energy, with oil prices down almost 60% on the middle of last year,
Energy prices plunged 8.9% in January.
If food and energy are stripped out of the calculations, eurozone prices were still rising at an inflation rate of 0.5%, down from 0.7% the month before.
The eurozone has only once before experienced deflation at these levels, in July 2009, as the region first went into recession following the financial crisis.
Last week the European Central Bank (ECB) launched a programme aimed at pushing prices back up – known as quantitative easing – through which it injected around 1 trillion euros into the economy.