Finnish Customs said they suspect the smuggler behind the 1,400 Subutex tablets seized at Helsinki Airport in September had also imported another batch of 2,800 pills, seized earlier in Southwestern Finland.
Subutex is a brand name of the opioid buprenorphine, a pharmaceutical used to treat opioid addiction. It has also become an abused street drug.
Customs officials said the individual had transported the drug from France to Finland via Spain. The alleged smuggler has been placed under arrest and is suspected of aggravated drug and narcotics offences.
Authorities said their preliminary investigation has ended and the case has been forwarded to prosecutors in Southwest Finland.
The value of all 4,200 of the seized tablets would have amounted to some 210,000 euros, according to officials, and would have amounted to about 16,800 single doses.