Hong Kong customs officers have seized drugs with a market value of about 5.9 million dollars (£5.2m) after searching electrical transformers.

The consignment containing about 76kg of crystal meth from Mexico was in transit at Hong Kong International Airport en route to Australia.

During an inspection on Friday, the officers found the haul concealed in false compartments inside three transformers.

Inspector Lam Kai-shan said the transformers appeared suspicious when they were X-rayed.

“We only saw simple structures but could not see other components that should have been there, such as high voltage cables or coils of wire,” he told reporters.

Police in Australia said the street value of the drugs would have soared to 68 million Australian dollars (£38m) in the country.

“We are now working together and following every lead to find those responsible for this importation,” Detective Superintendent Timothy Underhill of the Australian Federal Police said.

“Someone in Australia must know about this shipment, and we are very interested in talking to them.”

He said said Hong Kong officers found the drugs after receiving intelligence from Australian police and other agencies. The air cargo shipment was due to be delivered to an address in the western Sydney suburb of Blacktown.