TOKYO (AP) — Toyota Motor Corp. said Wednesday its subsidiary Daihatsu will suspend shipments of all its vehicles in and outside Japan in a damaging safety scandal after an investigation found improper testing involving 64 models.

The safety test irregularities earlier this year prompted an independent panel investigation, which found widespread and systematic problems.

Toyota, citing results of the panel, said its probe found 174 new cases of irregularities in safety test and other procedures in 25 test categories, in addition to the problems reported earlier.

"We are sorry to have betrayed the trust of our customers," Daihatsu President Soichiro Okudaira told a news conference Wednesday. He acknowledged the cheating on safety testing and procedures is tantamount to neglect of safety certificates.

"We take it very seriously as the problem that has shaken the foundation of an automaker," he said.

A lawyer and a member of the probe team, Makoto Kaiami, who also attended the news conference, said workers under pressure to meet management demands for tight development deadline resorted to cheating, and that the management should take the blame.

The issue first emerged in April when Daihatsu reported improper testing on the door lining. Problems in the side collision testing also surfaced in May, officials said.

The problems were found in 64 models and three engines of vehicles, including 22 models and an engine sold by Toyota, the company said in a statement. The investigation also found that the problems involved some models for Mazda Motor Corp. and Subaru Corp. sold at home, as well Toyota and Daihatsu models sold abroad.

Daihatsu is Toyota's unit specializing in small cars and trucks that are popular in Japan.

Toyota expressed "sincere apologies."

"We believe in order to prevent recurrence, in addition to a review of certification operations, a fundamental reform is needed to revitalize Daihatsu as a company," Toyota said.

Toyota said it will take a significant effort, including a review of management and business operations as well as the organization and its structure, as well as mindset of employees and that the company will provide full support to revitalize Daihatsu.