The new Toyota Tundra TRD won't be impacted by the Kobe Steel scandal. The company did not say which engines used the affected products. All in all, Kobe said the products were delivered to more than 200 unidentified companies. It could also undermine confidence in Prime Minister Shinzo Abe's moves to improve corporate governance as part of his programme of Abenomics.

According to Kobe Steel, the falsification was carried out at four Japanese factories. "Going forward, this will be a body blow to Japanese shares". A spokesman said: "We are rapidly working to identify which vehicle models might be subject to this situation and what components were used". Shares in the company fell 22 percent on Tuesday to 1,068 yen (£7.20; $9.50), wiping nearly a billion dollars off its market value.

After Kobe Steel Co. said Sunday that it had falsified data related to strength and durability of some aluminum and copper products, customers including Toyota and Mitsubishi Heavy Industries said they are investigating the impact on safety of their products. The products account for 4 percent of shipments of aluminum and copper parts as well as castings and forgings.

"These are improper actions that could shake the foundation of fair trade", Yasuji Komiyama, director of the industry ministry's metal industries division, told reporters at a briefing on the revelations.

"Aluminum is a strategic business for Kobe Steel", said Irisawa at Tachibana Securities.

It said the products did not comply with the specifications that had been agreed between itself and the affected customers.

Boeing said in a statement it was working "with our suppliers since being notified of the issue".

Major manufacturers involved in the defense industry, including Mitsubishi Heavy, Kawasaki Heavy Industries Ltd. and IHI Corp. have been found using the aluminum products in question.

Also Mitsubishi Heavy Industries Ltd., which is charge of the MRJ regional jet and the H-IIA rocket launched by Japan Aerospace Exploration Agency on Tuesday for a satellite, said the firm's aluminum was used but no defects were found yet as the launch was a complete success according to a spokesperson, Genki Ono.

Smaller Japanese automaker Subaru said that it used Kobe Steel products not only for vehicles sold to retail customers but also in aircraft.

"With a string of negative surprises at Kobe Steel lately, we believe investors are likely to distrust management even more due to this latest incident, despite emerging signs of earnings improvement in the steel and construction machinery segments", JPMorgan's Mori wrote.

It is now unclear what impact the scandal will have on Kobe´s business performance.

The steelmaker has reported losses in the last two full financial years but is expecting to return to profit in the current period. In the year ending in August, it affected...

Honda said it used falsified material from Kobe Steel in auto doors and hoods while Mazda Motor Corp. confirmed it uses aluminum from the company.