Toyota's subsidiary Daihatsu has suspended shipments of all its vehicles in and outside Japan after an investigation found rigged safety testing dating back over three decades.

Three engines and 64 models were involved in the scandal, with some of them bearing marques including Toyota and Subaru, according to a third-party committee's probe.

The models are sold in countries including Japan, Malaysia, Thailand, Mexico and Uruguay.

Daihatsu said on Wednesday that the probe found 174 new cases of irregularities in safety tests and other procedures in 25 test categories, on top of problems reported earlier.

The problem first emerged in April when Daihatsu reported improper testing on door linings. Problems in the side collision testing also surfaced in May.

"We are sorry to have betrayed the trust of our customers," Daihatsu President Soichiro Okudaira told a news conference on Wednesday.

He acknowledged the cheating on safety testing and procedures was tantamount to neglect of safety certificates.

In a statement on the same day, the carmaker said it recognizes the extreme gravity of these irregularities, vowing to make sweeping reforms to its corporate culture.

Toyota said it will review Daihatsu's management and business operations, organization and structure, as well as the mindset of employees. It will provide full support to revitalize Daihatsu, it said.

It is the latest of safety or other violations found at least five of Japan's major automakers in recent years, including Mitsubishi and Suzuki.