JAKARTA: Bird lovers would not be pleased to read this story.

Police in Indonesia have arrested a man they suspect was smuggling rare birds inside plastic bottles.

The man was allegedly caught carrying the live birds on a passenger ship near the city of Surabaya.

They included 21 yellow-crested cockatoos, which are listed as endangered. They were kept inside bottles to stop them from flapping. The birds are known to sell through legal channels for as much as $1,500 each.

Customs officials said the haul also included an unspecified number of green parrots. The exact number of yellow-crested cockatoos in the wild is not known, but the International Union for Conservation of Nature place it on their critically-endangered list.

Birdlife, a nature conservation group, say the birds' numbers are dropping due to “unsustainable trapping for the cagebird trade.”

In 2013, two Indonesian military employees were given a warning after they were found to be running a bird-smuggling ring on board a military aircraft. Bags containing rare birds were found when the plane refuelled in Australia.