A Japanese machine manufacturer and its president were referred to prosecutors Tuesday over an attempt to export to China motors that could be used for military-purpose drones, investigative sources said.

The products made by Tokyo-based Tonegawa Seiko Co. could have been delivered to a firm which conducts business with the Chinese People's Liberation Army, according to the sources.

Photo shows the building of machinery maker Tonegawa Seiko Co. in Tokyo on July 6, 2021. (Kyodo)

Since 2006, the company has exported about 11,000 servo motors, widely used to allow for precise control of angular position, to countries including China and the United Arab Emirates. The machinery maker has made at least about 340 million yen ($3.07 million) in sales since 2014, according to the police investigation.

Haruo Bando, the 90-year-old president of the company, allegedly tried to export motors in June last year, ignoring the Economy, Trade and Industry Ministry's request two months earlier to submit an application for an export permit, the sources said.

The trade ministry said the same day it has filed a criminal complaint against Tonegawa Seiko with Tokyo police over its attempt to export 150 motors, worth about 5 million yen, without government permission in violation of the foreign exchange and foreign trade law.

The company submitted a false report to the Tokyo Customs that it was not requested to submit the application. The Tokyo police in December conducted a house search and made inquiries to the firm on a voluntary basis.

"We forgot to have received (the request). It is true that we broke the law," Bando told Kyodo News.

The company may face a trade ban of up to three years, according to the trade ministry.

The United Nations had pointed out in a report released in January 2020 that motors made by Tonegawa Seiko have been used in Iranian reconnaissance drones.

A servo motor made by the company was found in an Iranian drone that crashed in Afghanistan in October 2016, and 60 motors sent to Yemen were seized in the UAE in November 2018, according to the U.N. report.

The 150 servo motors heading to China were likely to be used in unmanned aerial vehicles for spraying pesticide, according to the sources.