The figure is worse that a previous estimate of 9.6% and far higher than the 8% target agreed in Athens in financial rescue of the country.
The data come as Eurostat Unveils official statistics of the debt for the European Union.
The European Statistical Office also raised deficits in the United Kingdom for the past four years and spending military how in question had been accounted for.
"Eurostat expresses a reservation on the quality of data reported by the United Kingdom", the Agency said.
Eurostat said it is concerned about the timing of when military expenditures have been recorded, saying that they must be on a "delivery" basis, but not the amount being recorded.
The cost of bailing out of Northern Rock and Bradford & Bingley was more than previously reported, the European Agency said.
A total of 4 euros (£ 3 5bn, MD $5) has been added to the loans estimated the United Kingdom since 2007, according to Eurostat figures.
The United Kingdom for 2010 deficit was estimated at 10.4% of the gross domestic product - the third highest level in the EU.
Vicious circleIn Greece, level of debt is passed to 142,8% domestic product gross of the country of 127.1% previously.
Continue reading the main historyData for 2010. Source: Eurostat
The Greek Government reduced expenses in a chain of drastic cuts and tax rises required by European peers and Fund International Monetary in its bailout last year.Measures have managed to make the deficit fall to 15.4% of GDP in 2009, but did still not far from what was hoped.
Two years cost the Greece of borrowing rose more in bond markets in more than 23% per year after the publication of data.
The level indicates that the markets believe the debts of the country are difficult to manage and Athens is very likely to impose losses on holders of bonds when its existing loans to bail out expire them in 2013.
The Greek Government blamed excess borrowing on a recession in the country, which proved to be deeper than expected.
"The Greek Government remains committed to its deficit targets," the Finance Ministry said in a statement.
"All necessary measures in this direction are recorded in the budgetary strategy in the medium term to be submitted to Parliament by May 15."
Many economists point out the vicious circle that Greece is taken in, by which Government austerity worsens recession, which in turn increases the deficit.
UnprecedentedZone euro as a whole, public deficits fell to an average of 6% to 6.3% the previous year, reflecting the first year of pan-European effort to bring public finances under control through austerity measures.
Despite this, levels of public debt as a percentage of economic output has increased in the course of 2010 to 85.1% of 79.3%, low growth and the cost of interest payments.
Meanwhile, Eurostat data also painted a dark image to the Republic of Ireland, whose deficit of 2010 was confirmed to a unprecedented 32.4% of GDP.
The level of new loans - double what had been recorded the previous year - has been largely due to the losses of State-owned Irish banks.
As the Greece, the Portugal - which is becoming the third member of the euro area to receive a bailout - also exceeded its target of 7.3%, with a deficit of 2010 by 9.1%.
As the Greece, Portugal, and the Republic of Ireland also saw their borrowing costs increase after the announcement of data, each light on the performance of the obligations to five years approximately 11.5% increase of deficit.
However, it is good news for the Spain, that many see as next in line to becoming stuck in the quagmire of debt in the euro area.
Madrid has managed to reduce its deficit at 9.2% of the GDP, beating 9.3% target it had set.