LONDON — The London real estate market was abuzz. A wealthy Greek banker wanted to spend up to £60 million (nearly $100 million) for a home, and was in a hurry to make a deal.


Real estate agents recall sifting the listings for some of the most prestigious, and expensive, properties in South Kensington, a favored area for London’s international set.


But the house hunter, Lavrentis Lavrentiadis, never made a purchase in the spring of 2011, agents say. Within months his failing institution, a small lender known as Proton Bank, was seized. The Greek government, suspecting that Mr. Lavrentiadis may have moved money out of the country, is now investigating his activities to determine whether he engaged in fraud and money laundering.


Greece, heavily in debt and desperate to track down money wherever it can, is leaving no stone unturned.


Mr. Lavrentiadis has denied the accusations, and his lawyer did not respond to questions about any interest his client might have had in London properties. But the Greek banker’s rumored flirtation with this city’s prime real estate market, and the frenzy it stirred among sales agents, is telling.


At the request of the Athens government, the British financial authorities recently handed over a detailed list of about 400 Greek individuals who have bought and sold London properties since 2009.


The list, closely guarded, has not been publicly disclosed. But Greek officials are examining it to determine whether the people named — who they say include prominent businessmen, bankers, shipping tycoons and professional athletes — have deceived the tax authorities by understating their wealth.


“These people have money and they are known — but it is not clear yet if they have violated any laws,” said Haris Theoharis, an official in the Greek Finance Ministry. Tax investigators have been examining the list to see whether there is any overlap between those who bought London properties and those already identified as being tax cheats.


The Greek government, under pressure from its international lenders to raise 13.5 billion euros ($17.4 billion) through tax increases and spending cuts, is intent on making the well-heeled share the burden. Studies have shown that the country may be forgoing as much as 30 billion euros a year in uncollected taxes, with a significant portion of that amount having been shipped out of the country as the affluent seek shelter from Greece’s financial storm.


This week, the government of Prime Minister Antonis Samaras opened an investigation into the bank accounts of more than 30 Greek politicians to determine whether they should be charged with tax evasion and the illegal accumulation of wealth.


The politicians on the list included the president of the Greek Parliament, Evangelos Meimarakis, creating an embarrassing distraction for Mr. Samaras’s coalition government. Mr. Meimarakis is a former defense minister who has also been implicated in accusations concerning a money-laundering network said to involve two other former ministers.


London, long a magnet for foreign real estate investors, has become a special focus for Greek officials trying to track down money taken from the country.


Bankers say that accounts in Singapore and even in the country of Georgia have become favorite destinations for fleeing funds, more so than the traditional haven of Switzerland, because the looser rules and regulations of those countries about accepting large sums of foreign money. But while Singapore and Switzerland have been reluctant to divulge information about its Greek clientele, the British government has been more cooperative in sharing its real estate records.


There is an air of desperation to this Athens fund-raising drive, which includes leasing out empty Greek islands and even putting up for sale the former residence of the Greek consul general in the tony London neighborhood of Holland Park. But with Greece’s membership in the euro at stake, every conceivable revenue-raising strategy is being pursued, even if it remains unclear how successful it will be.