A Japanese court on Wednesday ordered the Tokyo metropolitan government and the state to compensate the president of a Yokohama-based company and others for an unlawful investigation into alleged illegal export of items capable of producing biological weapons.

The Tokyo District Court awarded compensation totaling some 160 million yen ($1.1 million) to Masaaki Okawara, 74, president of machinery maker Ohkawara Kakohki Co., Junji Shimada, one of its former directors and the family of former adviser Shizuo Aishima, who died in February 2021 after falling ill during detainment.

Masaaki Okawara, president of machinery maker Ohkawara Kakohki Co., speaks to reporters outside the Tokyo District Court on Dec. 27, 2023. (Kyodo)

In the trial, which focused on whether police and prosecutors arbitrarily interpreted the regulation for export control to build a case against the three, the court ruled that their arrests and indictments of the three individuals between March and June 2020 were all illegal.

Presiding Judge Tsuyoshi Momosaki criticized Tokyo police by saying, "Had they carried out investigations as typically required, they could have gathered evidence indicating that the device would not be subjected to export regulations."

Momosaki also said prosecutors went on to indict the three "without conducting investigations that are crucial to establishing one's guilt."

Okawara told reporters following the ruling, "I believe the court has judged appropriately."

"I hope that Tokyo police and prosecutors will thoroughly verify (their investigations) and, if possible, offer an apology," Okawara added.

The plaintiffs sought 560 million yen in damages in the lawsuit filed in September 2021, claiming the items in question -- spray dryers that can atomize liquids into a mist and then turn it into a powder -- were not subject to export restrictions.

Ohkawara Kakohki is Japan's leading maker of spray dryers, which are widely used to produce food products such as instant coffee, baby formula, medicine and ceramics.

The case took an unusual turn, with a member of Tokyo police's Public Security Bureau testifying during the trial that the allegations leveled against the three were "fabricated."

They had been arrested and indicted on suspicion of illegally exporting spray dryers capable of producing biological agents without authorization, but shortly before their first hearing in July 2021, prosecutors withdrew the indictment of Okawara and Shimada, saying that "doubts have arisen as to whether they are guilty of a crime."

The indictment for Aishima had been rescinded due to his death.

Okawara and Shimada spent 332 days in custody until they were released on bail in February 2021.