"We will check the credentials of every physician who qualified outside the EU and EEA (European Economic Area) and who has been licensed to practise in Finland over the past 20 years," Valvira medical advisor Liisa Toppila told AFP.
Valvira, the National Supervisory Authority for Welfare and Health, was responding to a furore that erupted last week when Finnish tabloids reported that a practising doctor, Esa Laiho, had fake credentials.
Tipped off by the media, Valvira discovered that the man did not graduate from a Saint Petersburg university as he claimed, nor did he even attend the institution.
Nonetheless, he had been granted a license to practise in Finland in 2003.
Valvira confirmed Monday that Laiho was struck off the Finnish medical register and now faces a criminal investigation.
The case has prompted ordinary Finns to come forward with suspicions of unqualified medical professionals, and a second man claiming to have graduated from a Russian institution was also found to have fake certificates.
The country's health minister has said she fears more cases will come to light.
The head of the Finnish Medical Association, Heikki Paelve, wants the authorities to verify the records of all doctors trained outside Finland, including from within the European Union.
"We understand that there have been similar cases in southern Europe, where some doctors have been found not to have all their papers in order," Paelve said in an interview with YLE interview.
In January 2010, Finnish police arrested and charged a young man who had duped patients and staff for almost a year at two health care centres in western Finland.
He later received an 18-month prison sentence.