A 43-year-old Japanese man was sentenced to one year in prison by a Hong Kong court Tuesday for smuggling 60 endangered turtles from Japan last year.

Naoki Hiraguchi was caught with 60 live Ryukyu black-breasted turtles that were placed in two cartoon boxes inside his checked-in suitcase as he arrived at Hong Kong's international airport on Oct. 26.

Hiraguchi in a hearing on Friday last week pleaded guilty to importing an endangered species without a permit. He claimed that he was helping a Japanese friend in Okinawa bring the turtles into Hong Kong for breeding purposes.

He was scheduled to testify on the claim Tuesday but decided against it at the last minute.

Deputy District Court Judge Emily Cheung ruled that the trafficking of the turtles was for commercial gain and the fact that they had to endure several hours inside the luggage compartment of the airplane during the flight would "expose them to risk of extinction."

"It's purely out of luck rather than good management that all 60 turtles survived...the journey," Cheung said. "I do not accept that the defendant was only doing a favor for his friend and I am satisfied that the 60 turtles were (brought) for commercial purpose."

One of the turtles later died "by natural causes," the court heard, while the rest were returned to Japan in March. They were estimated to have a total market value of between HK$510,000 (US$65,000) and HK$2.4 million.

The 12-month prison sentence would include the period he was detained since last October.

Hiraguchi appeared calm and nodded when the ruling was announced. His defense lawyer said they have not decided whether to file for appeal.

Japan listed the turtles as endangered species in 2000.

The Ryukyu black-breasted leaf turtle (Geoemyda japonica) is found only on three islands of Okinawa Prefecture where it has been designated as a "natural monument" since 1975. There has been concern among biologists over illegal capture and changes in its habitat.