Five people have been jailed in China after being found guilty of running an unlicensed online game server.

Shanghai Yetime Ltd, the firm that owns the licence to operate Priston Tale in China, claimed that the gang deprived the firm of $395,000 in income.

The scheme's ringleader, 33 year-old Yan Shaodong, bought a black market copy of the Japanese version of the game server in 2006, Chinese press reports said.

He then hired four developers to translate the game into Chinese and operated the illegal game servers.

Players can download and play Priston Tale free of charge, paying only for extra equipment to use within the game.

The game relies on two separate pieces of software: a client which runs on the player's PC; and a server which keeps track of all players and objects in the game world.

Shanghai Yetime quickly became aware of the unlicensed server and worked with police to track down the operators.

Despite the firm's claim that it had lost almost $400,000, Yan told the court that he had collected only $9,500 from players before being arrested in May 2007, and had made a loss after paying for the server software and staff salaries.

Yan was sentenced to two years in jail, the Shanghai Daily reported. His employees received lighter sentences.

Priston Tale was developed by Korean games firm Yedang and was launched in 2002 in Korea, Japan and China.

The title was among the most popular games of 2002 and 2003 in these countries, but by 2004 revenues had begun to fall as players moved on to new games.