A Mexican man has been arrested at Tokyo's Haneda airport after customs officers found about 200 lizards stuffed into 22 pairs of socks inside his suitcase.

Daniel Isaac Velasco Baltazar, 23, is accused of trying to bring the reptiles into Japan from South Korea on Saturday without declaring them, in breach of the country's customs law.

Tokyo's Metropolitan Police Department said he had admitted to importing them without permission.

One of the lizards was dead when the case was opened.

Nine of them were Mexican alligator lizards, also known as arboreal alligator lizards, a species found only in the highland forests of Mexico and listed under the Convention on International Trade in Endangered Species, which requires government permission for any cross-border sale.

The suspect reportedly told investigators he had bought the lizards in Mexico for between about 560 and 750 yen each (roughly £3 to £4). These animals are scarce in Japan and are said to change hands there for around 100,000 yen (£520).

Tokyo police were tipped off anonymously in late July that a Mexican national was attempting to smuggle lizards into the country in time for a reptile exhibition and sale.

Customs officers at Haneda were put on alert and searched his suitcase when he arrived, finding the animals inside socks and rolled in T-shirts.

The case appeared to contain species other than Mexican alligator lizards, and authorities are still working out what they were.

Mexican alligator lizards, bright green and slow-moving, live in the pine and oak forests of the Sierra Madre in central Mexico, where logging and collection for the pet trade have reduced their numbers. The species is classed as endangered.

Japan is one of the world's largest markets for exotic reptiles, and airport seizures of smuggled animals are not unusual there, with previous cases involving tortoises, snakes and turtles concealed in luggage.