Customs officers in Shenzhen have detained a Hong Kong man who said he tried to smuggle live crickets into China in his luggage so they could perform in a national contest in eastern Shandong Province.

The crickets were spotted in the man’s hand luggage by an X-ray machine at Futian Immigration Port, Sing Tao Daily reported. Eight of the insects were stored in four glass jars inside the bag.

According to customs officers, the man was heading to the National Cricket Fighting Competition in Taian, which ran from October 2-7. As he had no customs permit or quarantine document, the crickets were put to death and the man was detained for further investigation.

Doubts were reportedly raised over his story, as organizers do not allow crickets to be entered once competition has started. It is thought he had actually intended to sell the insects.

Cricket fighting competitions are very popular in China, with one insect sold for 100,000 yuan (US$14,442) in Shandong Province in 2017 and a second changing hands for 20,000 yuan (US$2,888) in Henan Province in March this year. The winner of the national competition was expected to earn 500,000 Chinese (US$72,301).