A man awaiting deportation to China at a Nagasaki Prefecture immigration center on Monday requested temporary release in consideration of the time he has already spent in custody.

Kim Yong Hwa, 46, has been detained at Omura Immigration Center since July 1998 on suspicion of illegally entering Japan. He is arguing his long-term detention is inappropriate, according to his lawyer, Seigo Yano.

Kim, who claims to have defected from North Korea 12 years ago to escape political persecution, is reportedly in poor health and undergoing treatment for high blood pressure. Japanese immigration authorities said China claims him as its citizen.

"The government's immigration policies are changing little by little, so if the temporary release is approved, it will be an epoch-making case," Yano told a news conference in Fukuoka. He was referring to a February decision by Justice Minister Hideo Usui granting special residence permits to four Iranian families who had overstayed their visas. Kim has filed a suit with the Fukuoka District Court seeking to annul the issuance of the Justice Ministry's 1998 order to deport him to China and reiterating his request for political asylum in Japan.