Jeroen Dijsselbloem admitted Brussels was at fault for its strict austerity measures which plunged one third of the population into poverty.
The Dutch politician, who was the President of the Eurogroup of finance ministers between January 2013 and 2018, said: “On reforms, we have asked a lot from the Greek people, too much.
“Reforms are hard enough to accomplish in a society with a well-functioning government, but this was obviously not the case in Greece.”
Greece, whose economy collapsed following the 2008 financial crisis that swept over the western world, received £258.24 billion (€288bn) in financial aid since 2010 making it the biggest bailout in economic history.
During the past eight years, Athens has gone through three bailouts, agreed in 2010, 2012 and 2015, with the European Union being its biggest lender.
The third international bailout, signed off by Prime Minister Alexis Tsipras, ended on August 20.
Despite years of cuts, the lending will be followed still by a new string of belt-tightening measures, including public sector redundancies, tax hikes and pension cuts, set to be implemented from January 2019.
Mr Dijsselbloem, who led dozens of lengthy emergency meetings discussing bailout programmes for Greece, Cyprus and Spain, dismissed those calling the end of the bailout programmes a “success”.
He said: “Greece is obviously not a success story.
“Their crisis has been so deep, that you can’t call it a success.”
Mr Dijsselbloem’s criticism comes after European Central Bank policymaker Jens Weidmann warned Greece still faces “a long road to recovery” after leaving its bailout programme.
Mr Weidmann said earlier this week: “The end of the third adjustment programme is not the finishing line, but a milestone on a long road to recovery.
“The route to future prosperity for Greece could lie in proving in the years ahead that it can stick to a sound fiscal path.”
During the crisis, the Greek economy shrank by a quarter, pushing a third of the population into poverty and driving thousands to move abroad.
The Lancet, an organisation focused on public health research, highlighted the stark consequences the austerity had even on the health of Greek people.
In the last 18 years, Greek mortality has significantly worsened.
In 2000, the death rate per 100,000 people was 944.5.
By 2016, it had risen to 1174.9, with most of the increase taking place from 2010 onwards.
By contrast, global death rate fell during this time.
The report said the additional deaths are due to a range of reasons, including “adverse effects of medical treatment, self-harm, and several types of cancer.”
Greek adults aged between 15 and 49 had increased mortality due to HIV, several treatable neoplasms, all types of cirrhosis and neurological disorders.