More than 250 smuggled iPhones were found in the luggage of four Americans by customs officers at the Tan Son Nhat Airport in Ho Chi Minh City, Vietnam, on Sept. 12.

The four American men were unable to provide legitimate documentation for the iPhones, VN Express reported. The haul of the new iPhone XS and iPhone XS Max models was estimated to be worth about VND7 billion (US$300,000).

The deputy head of the Customs Agency at the airport, Tran Ngoc Anh, presented details of the case to local media on Sept. 25, saying the four American citizens traveled on flights CX767, CI781 and BR395 from the US and arrived in Ho Chi Minh City on Sept. 12, The Saigon Times reported.

Tran added that imported mobile phones have to be declared upon arrival and travelers carrying more than two cell phones worth more than VND20 million have to pay tax and declare the goods.

He also said those who fail to do so will have to re-export the phones out of Vietnam. Authorities are investigating the source of the smuggled iPhones.