A ring exporting currency illegally via Sofia airport was uncovered in a special police operation, Sofia City Deputy Prosecutor Roman Vassilev told a news briefing on Tuesday.

The enforcement operation, conducted by officers of the State Agency for National Security (SANS) and the Interior Ministry under the leadership of the Sofia City Prosecution Office, resulted in the arrest of three Chinese and Bulgarian customs and airport officers, Vassilev said. He did not say how many customs officers were detained, BTA reports.

A batch of more than 350,000 euro was to be smuggled via Sofia Airport on Tuesday. The investigators knew of the currency smuggling ring for two months, Vassilev said.

Vesselin Markov of SANS said that the enforcement operation led by the Sofia City Prosecution Office has been going on for a month and a half. During the period of surveillance, money was allowed to be exported two or three times in order to localize the persons involved.

The money came as proceeds from the sale of contraband goods imported from China, according to Markov. Customs duty and taxes were paid for part of the goods, and the rest were distributed illegally, mainly through the Iliyantsi wholesale market. The proceeds were then exported back to China. The enforcement operation in Sofia continues.