Five men from Eastern Europe face charges of manufacturing more than 1,800 forged passports. Nearly a third of the passports - 562 - were Finnish passports.
Also found were 428 forged Portuguese passports, as well as a number of British, Korean, Latvian, Slovenian, Albanian, Danish, Greek, Italian, Belgian, and French travel documents.
British police estimate that the street value of the passports would have been more than a million pounds, or about 1.5 million euros.
Finland's National Bureau of Investigation was still waiting for the British authorities to contact them about the matter. NBI investigator Jyrki Rostila told YLE that the seizure is by all accounts the largest case of forgery of Finnish passports. He said that with its reputation of stability, Finland is an attractive target for passport forgers.