Customs officials on Tuesday said they have seized 100 kilogrammes of suspected methamphetamine at the airport last month, in a major drug bust said to be worth around HK$57 million.

Officers said they found the suspected drug inside a milling machine that arrived from Canada.

A 34-year-old man, who claimed to be a logistics officer, was arrested. He's since been released on bail pending further investigation.

Lau Hei-yiu, a senior inspector of the customs' airport command, said officers became suspicious when they learnt that the milling machine had come all the way from Canada.

"We found that the important components of the milling machine had been removed, and so it couldn't even function properly. Even so, someone was still willing to pay for it to be shipped from Canada. So we believe there were untold secrets behind," she said.