A man believed to be the leader of the largest Chinese crime syndicate in Japan has been served a fresh arrest warrant on suspicion of entering false information on a government document, police said Wednesday.

Wang Jiande, 31, allegedly submitted a forged passport featuring a false name to the Katsushika Ward Office in Tokyo on Aug. 4, 2000, to obtain an alien registration card, according to police.

Wang, who has already been indicted on a separate immigration law violation, is believed to be the leader of a crime syndicate with roots in China's southeastern province of Fujian, investigators said.

Investigators are also questioning Wang over his alleged leadership of a gang comprising some 50 Chinese criminals operating in Japan. Members of the gang are believed to have committed a variety of thefts, robberies and other offenses.

Police added that they are trying to unravel the organization's operations by interrogating suspects in two attempted murder cases arising from gunfights in Tokyo in July 2000 and last January.