Police in Indonesia have reportedly arrested a man for trying to smuggle rare birds stuffed inside of plastic water bottles.

The bottom of the water bottles had been cut off in order to squeeze in the nearly two dozen live birds, mostly yellow-crested cockatoos, AFP reported. Authorities told the news agency that the 37-year-old suspect, whose name hasn’t been released, admitted to carrying two birds for his friend and he could face five years in prison for the offense.

“The birds were still alive then but some were already very weak,” Tanjung Perak police spokeswoman Lily Djafar told CNN.

The cockatoos, along with one green parrot, were found in bottles packed inside of a crate on a boat and then sent to the country’s natural resources conservation office, AFP reported. The office confirmed to CNN that seven died later.

Police caught the suspect getting off a vessel during an anti-smuggling operation by custom officials at a port in Surabaya, Indonesia, CNN reported.

The International Union for the Conservation of Nature has listed the yellow-crested cockatoos, also known as Cacatua sulphurea, as critically endangered. The ranking is one grade below extinct in the wild.

Native to East Timor and Indonesia, the bird has suffered “an extremely rapid population decline, owing to unsustainable trapping for the cage bird trade,” according to the IUCN.