Official figures show that there was an annual fall in euro zone prices in September for the fourth month running.
The drop was 0.3%, according to figures from the Eurostat data agency which confirmed an initial estimate.
Monthly inflation was at absolute zero, however, in September 2009, and analysts said the slight change from the 0.2% annual fall registered in August was likely to prove a blip.
The current run marks the first such decline for consumer prices since households began paying for goods in euro notes and coins at the start of 2002. August's price fall was far smaller than the record 0.7% recorded in July.
