Three suspected Indonesian traffickers were arrested after customs officials thwarted the bid to transport the animals to Thailand in an operation off Langkawi on Friday.

The unusual cargo included two “frightened-looking” orangutans and dozens of baby saltwater crocodiles, wildlife official Mohamad Zaki Rahim told AFP.

There were also about 350 sugar gliders – a type of small marsupial – cockatoos, parrots and parakeets found in boxes on board, he said, adding the smugglers intended to sell all the animals as pets.

The smugglers were seeking to transport the animals under cover of darkness in a cargo vessel from the vast, jungle-clad Indonesian island of Sumatra, through the Melaka Strait to Thailand, customs chief T Subromaniam told The Star.

But customs officers received information about the boat and intercepted it, Subromaniam said.

The arrested Indonesians, who were on the vessel when it was stopped, are expected to be charged in court with breaking wildlife laws and could face up to 10 years in jail, Zaki said.

Elizabeth John, spokesman for wildlife trade watchdog Traffic, said the number and variety of animals seized showed “how tremendous the pressure is on wildlife due to demand for pets”.

Authorities in Malaysia regularly thwart smuggling attempts, but finding 400 animals at the same time is unusual.

In June 2017, Thai authorities nabbed a Malaysian trying to smuggle two juvenile orangutans and some 60 other animals in a taxi through the country’s southern border.