Six men have gone on trial in Beijing for allegedly participating in the illegal ivory trade.

Two of the men, both surnamed Zhao, are suspected of selling more than 100 kilograms of ivory to the other four defendants in Weihai, Shandong province, in May last year, according to a statement issued by Beijing Xicheng District People's Procuratorate.

On May 21, 2015, Beijing police received a report that a white car would be delivering ivory to a location in the capital's Daxing district.

That night, police found the car, seized three boxes of ivory and arrested two suspects, the statement said.

The other four suspects were detained between May and August last year, and the money involved in the case could be more than 2.6 million yuan ($388,163), according to the statement.

The six suspects made the deal in early May 2015, and the four buyers allegedly drove to Shandong to see the ivory on May 20, it added.

Wang Zhaohua, a prosecutor responsible for the case, said that all the suspects knew that they were trading in endangered wildlife products and had a clear division of labor.

"So this has been identified as a joint offense and they should be prosecuted at the same time," he said.