A Japanese company admitted last night that it had falsified data after its seats, used by dozens of international airlines, failed safety tests. It is understood that about 150,000 suspect seats made by Koito Industries have been installed in 1,000 Boeing and Airbus aircraft owned by 32 carriers in 24 countries.

Singapore Airlines, Continental and All Nippon Airways are thought to have delayed the introduction of new aircraft because of problems with Koito seats.

British Airways, Virgin Atlantic, bmi and easyJet said that they were not affected.

Like all aircraft seats, the Koito products were subjected to a series of tests for strength and fire resistance, but the results of the tests, the company has admitted, were fabricated.

Takashi Kakegawa, the company’s president, said last night that: “The whole section in charge was systematically involved [in the falsification].” He added that the practice had begun because orders had increased and delivery schedules had tightened.

In its attempt to fool regulators, the company is understood to have developed software that would display acceptable-looking readouts on screens whenever inspectors from the Transport Ministry came to observe the testing procedures.

The most serious of the fabricated data is thought to have arisen from the dynamic load tests that simulate a human body being thrust into the seats at high speeds. The seats did not meet the necessary standards, but the test had been rigged to persuade the inspectors that they did.

Although the Japanese Government does not believe that an emergency recall will be necessary — or for airlines fitted with the suspect seats to stop flying — the company has been told to stop shipments of new seats that have not been tested properly.

The company has also been issued with an official business improvement order — a humiliating punishment that has been known to break smaller companies.

The Japanese Government is in consultation with aviation authorities in the United States and Europe over how to deal with the suspect seats already fitted.

The revelations are expected to deal yet more harm to Japan’s global reputation for workmanship and concern for customers — both of which have been tarnished by the twin crises affecting the accelerators and brakes of Toyota cars.

Koito Industries is a member of the Koito Manufacturing group, which derives half its business from sales of parts to Toyota.

The elaborate fraud carried out by the Yokohama-based company emerged yesterday after a seven-month government inquiry.

The two domestic Japanese carriers, Japan Airlines and All Nippon, are understood between them to have fitted 300 aircraft with the seats.

The Transport Ministry said that Koito had failed to perform a critical part of one of the tests and had applied the results of previous tests to newer products that had not been subjected to the same standards.

Officials also speculated that falsification may have started in the mid-1990s. The scam came to light last summer after an employee turned whistle-blower.