Euro zone inflation fell deeper into negative territory in September, official data has shown, amid plummeting demand due to the coronavirus crisis.

The EU's Eurostat data agency said inflation fell to -0.3% last month, a drop from -0.2% in August and way off the official target of near 2%.

The descent into deflationary territory will put pressure on the European Central Bank to draw up further stimulus measures, already at €1.35 trillion, and should encourage governments to spend more.

Policymakers worry about falling prices as they can encourage consumers to hold off making purchases in hopes they fall further, which can lead to a spiral of dropping economic activity, employment and prices.

Over the longer term, the ECB sees inflation averaging just 1.3% in 2022, still far below its target, which has triggered calls for reform.

ECB chief Christine Lagarde said this week that the euro zone should have an inflation goal "that the public can easily understand" and is calculated in a way that better reflects people's everyday lives.

Inflation in the 19-nation euro zone has stayed stubbornly low for years despite unprecedented economic stimulus from the ECB, keeping the target well out of reach and fuelling calls for a rethink.

Pursuing a less strict inflation target would follow in the footsteps of the US Federal Reserve which last month pledged more leeway, allowing inflation to rise above 2%.

According to Eurostat, energy prices were down 8.2% in the year to September, reflecting the sharp drop in oil prices that has occurred since Covid-19 severely hindered demand.

When energy is excluded from the index, the bloc recorded inflation of 0.6% in the month.

Food, alcohol and tobacco prices were up 1.8% in September, while unprocessed food saw the biggest price increase at 3.1%.

The member state which saw the sharpest drop in inflation in the month was Greece, which was down 2.3%. Meanwhile inflation was highest in Slovakia, where prices rose by 1.5%.

In Ireland, inflation fell by 1.1% during the month, according to Eurostat.