Daihatsu, the Japanese automaker owned by Toyota, has halted domestic production after admitting it forged the results of safety tests for its vehicles for more than 30 years, CNN reported.

The brand, best known for manufacturing small passenger cars, has stopped output at all four of its Japanese factories as of Tuesday, including one at its headquarters in Osaka, a spokesperson told CNN.

The shutdown will last through at least the end of January, affecting roughly 9,000 employees who work in domestic production, according to the representative.

The move comes as Daihatsu grapples with a deepening safety scandal that Toyota says “has shaken the very foundations of the company.”

Last week, Daihatsu announced an independent third-party committee had found evidence of tampering with safety tests on as many as 64 vehicle models, including those sold under the Toyota brand.

As a result, Daihatsu said it would temporarily suspend all domestic and international vehicle shipments and consult with authorities on how to move forward.

The scandal is another blow to the automaker, which had admitted in April to violating standards on crash tests on more than 88,000 cars, mostly sold under the Toyota brand in countries such as Malaysia and Thailand.