Greece's state statistics agency has today drastically revised downwards the economy's third-quarter contraction to 0.9% from 0.5% previously.
"These differences are on account of using new data, not available at the time of the flash estimate," the Elstat agency said.
It cited a mixture of September balance of payments data, service turnover and jobless figures as factors for the downturn.
In an annual comparison, Greek output fell by 1.1% from the third quarter of 2014, Elstat said.
The flash estimate on November 13 had pointed to a 0.4% drop from last year. The data is consistent with European Commission forecasts that Greece will fall back into recession in 2015 after a brief respite last year.
The Commission is banking on a 1.4% contraction in 2015 and a further drop of 1.3% in 2016.
Greece's own 2016 budget, to be approved by parliament in early December, foresees "near zero" growth in 2015 and a 0.7% economic downturn next year.
Although Greece had a record tourism year, the gains were lost to economic uncertainty as the leftist government of Alexis Tsipras clashed with international creditors in June and imposed capital controls.