Twenty Filipinos are under investigation following a major drug seizure on the Norwegian-flagged cargo vessel M/V Lunita which was allegedly carrying two tons of cocaine.

According to Department of Migrant Workers Secretary Hans Cacdac, the substance was discovered in the engine room of the vessel. The ship’s captain was reported to be a Filipino national.

In a statement on 3 April, the J.J. Ugland shipping company that owns the vessel confirmed it arrived at the port of Okgye, South Korea, on 2 April and was searched by South Korean authorities.

“The authorities found a large amount of cocaine hidden on board. An investigation is ongoing, and it is still unclear how the drugs came aboard our vessel. We are working with the relevant authorities to assist the investigation, both in South Korea and in other affected jurisdictions,” said J.J. Ugland in a statement.

Cacdac said the Filipino seafarers are being assisted by a lawyer provided by the company, with the Philippine government set to assign them another lawyer in the next two days. The DMW will also reach out to the crew’s families.

According to South Korea’s Customs Office, a team of 90 narcotics officers and two drug detection dogs boarded the vessel and discovered a concealed compartment behind the engine room where 57 boxes were found containing cocaine that was confirmed in field tests.

Authorities estimated the drugs’ market value at around KRW 1 trillion (approximately US$740 million). This is considered the biggest drug haul in South Korea.

The tip reportedly came from the US Federal Bureau of Investigation and Homeland Security Investigations. Before arriving in South Korea, the M/V Lunita had been in Mexico, Ecuador, Panama and China.