An inquiry could deepen the problems at Kobe Steel. The company already faces an investigation in the United States, where the Justice Department has asked its American unit for records related to any substandard metal sold there.

Kobe Steel said last year that some of its managers lied about the quality of aluminum, copper and other products it sold to companies around the world in order to meet its own lofty quality targets. The metals have gone into products including passenger jetliners, cars and high-speed trains.

The company has said that the deceptions went back decades. It blamed an emphasis on short-term profits and a corporate culture that discouraged front-line employees from questioning the decisions of more senior managers. It vowed to shake up its management practices, and last month it named a new president, a longtime Kobe Steel executive named Mitsugu Yamaguchi, to replace Hiroya Kawasaki, who stepped down to take responsibility for the scandal.

No deaths or safety incidents have been blamed on the products, which still met government safety standards. But they set off a series of disclosures about falsified data at other companies that are known for supplying high-performance parts. They include Toray Industries, a manufacturer of materials like carbon fiber, and Mitsubishi Materials, which makes components for cars, aircraft and industrial equipment.

They also came a year after Japan’s vaunted auto industry disclosed its own data falsification issues. Mitsubishi Motors and Suzuki Motor both said in 2016 that managers there cheated on fuel economy tests. And last year, Nissan and Subaru said they allowed unauthorized employees to conduct safety tests on finished vehicles.