The Toyama Prefectural Police chief approved the release of an alleged drug user in 1995 by allowing investigation documents to be falsified to say the suspect was let go because of his health condition, police sources said Thursday.

Masafumi Ueda, head of the Chubu Regional Police Bureau, who was chief of the prefectural force at the time, affixed his seal to the paper containing false information regarding the release of Shinichi Tsuchida, 39, a civil engineer, the sources said.

Ueda had been briefed by subordinates that Tsuchida should be released because he was supplying information to police on another drug-dealing case involving gangsters being investigated by the Toyama Police Station, the sources said.

In addition to Ueda, then criminal investigation section chief at the Toyama police, Minoru Takamatsu, and four other senior officers stamped their seals on the paper, the sources said.

Prefectural police suspect these acts may have constituted forgery of public documents.

Ueda declined comment on the sanctioning of the falsified documents, but a senior Toyama police officer, who is questioning officials in connection with the 1995 case, said Ueda must have known about it.

Tsuchida was arrested by Yatsuo police on May 17, 1995, after a urine test showed he had used stimulants, according to investigations.

Police seized drugs in the city of Toyama based on Tsuchida's depositions, but he was released the next day.

Meanwhile, a former head of the Toyama Police Station was found dead Tuesday morning at his home in the city of Toyama in what police believe was a suicide.

Investigators also decided Thursday to press charges against Tsuchida for his alleged stimulant drug use in 1995. Tsuchida was arrested in August and has been indicted over another case of amphetamine use.