The pair had flown in from Jakarta, Indonesia, on Sept. 30, Santanee Phairattanakorn, director of the Suvarnabhumi Airport Passenger Control Customs Office, said on Oct. 4, according to The Nation.

The passengers have not been named and their nationalities were not disclosed.

The Customs Department alleges the two failed to comply with a Finance Ministry notification on exchange control and a regulation on moving currency and negotiable instruments into or out of Thailand, and cited the Exchange Control Act and the Customs Act.

Travelers may bring any amount of currency into Thailand but must declare foreign currency worth more than $15,000.

A view of Suvarnabhumi Airport in Bangkok, Thailand. Photo by Unsplash

The arrests follow an order from Deputy Prime Minister and Finance Minister Ekniti Nitithanprapas for customs officers to tighten checks on Thai and foreign currency and negotiable instruments entering or leaving the country, Khaosod English reported.

The measures are meant to prevent cross-border cash smuggling and possible international money laundering, it said.

Customs Department Director General Phantong Loykulnanta has told officers to step up searches, particularly for cash concealed by air passengers, the department said.

Santanee said the department is continuing surveillance and screening of high-risk passengers to prevent cross-border currency smuggling, according to Thai PBS World.

The department urged anyone carrying Thai baht, foreign currency or negotiable instruments into or out of Thailand to comply fully with the rules.