Mexico City: Mexican authorities arrested a Chinese airline passenger after a strong smell emanating from his suitcases led to the discovery that he was transporting body parts from hundreds of endangered totoaba fish.

Police at the Mexico City international airport "found 416 totoaba swim bladders in [the passenger's] two suitcases," the prosecutor general's office said in a statement Wednesday.

The totoaba's swim bladder - an organ certain fish species use to control their buoyancy - is prized in Chinese traditional medicine for its purported rejuvenating qualities, and can fetch up to $20,000 (Dh73,460) on the black market.

The man was arrested and then granted conditional release after paying a $600 fine, the statement said.

The critically endangered totoaba is native to the Gulf of California, off Mexico's western coast.

Authorities say drug cartels and heavily armed poachers are involved in trafficking its swim bladder.

The nets used to catch the totoaba have also contributed to the demise of another critically endangered species, the vaquita marina, the world's smallest porpoise. Researchers estimate just 30 of them now remain.