Greek development minister Adonis Georgiadis, who recently visited China, said the Bank of Greece had concluded that "the use of bank terminals does not violate Greek or European law. If it is violating the Chinese law, this is a matter for China."

"We are not allowing entrance to criminals or money for which we do not know the source," Silva said. "Exceptions can happen but it will be one in 10,000 or two in 10,000 and of course those are the ones that go public."

"They like to stay in Athens and the suburbs, forming little Chinatowns. They are buying blocks of flats, where all the owners are Chinese," said Anny Avgouli, migration policy manager for a law firm, Dedes, that has a special department for golden visas specifically for Chinese customers.

In a report earlier this year, the European Commission singled out Cyprus, Bulgaria and Malta, complaining that wealthy candidates for residency or citizenship do not face adequate security and background checks.

China and Greece have been building progressively closer trade and investment ties for more than a decade, ever since two main container terminals at the port of Piraeus were sold to Chinese shipping giant Cosco in 2008.

To apply, non-EU nationals must make a significant investment in Portugal, such as buying real estate. They are then given residency rights and are allowed visa-free travel throughout Europe's Schengen area.

Britain scrapped golden visas in February following the Russian invasion of Ukraine amid concerns about the inflow of illicit Russian money. Portugal suspended golden visas for Russians, but 431 had already benefited from the scheme since the time of its launch, according to SEF. ($1 = 0.9497 euros) (Reporting by Catarina Demony; Editing by Crispian Balmer)

The Portuguese branch of anti-corruption group Transparency International (TI) has said the program could be used for money laundering, while the European Commission has said it considers such schemes a potential security risk.

LISBON, Dec 11 (Reuters) - Investments through Portugal's "golden visa," which gives wealthy foreigners residence rights, jumped nearly 50% last month, data showed on Sunday, as the government considers whether to scrap the controversial scheme.

Vasco Silva, the CEO of Kleya, which helps foreigners move to Portugal, said his company had received many queries about what was going on, adding that some investors had rushed their decision just incase the program was altered or binned.