Heavy machinery maker IHI Corp. said Friday it has found 211 cases in which airplane engines were improperly inspected over the past two years, including by uncertified workers.

It has also found cases where qualified workers did not follow the prescribed order in conducting maintenance work and where inspectors falsified the inspection dates, according to an interim report released Friday.

The supplier of Boeing Co. and Airbus S.A.S. said a shortage of inspectors and other factors led to misconduct that began in January 2017, at the latest, in a Tokyo factory where IHI provides maintenance for around 100 to 150 engines a year.

IHI first admitted to the misconduct on Tuesday.

There are no problems in the capability and performance of the affected engines, the company said.

IHI is the latest major manufacturer to become embroiled in a scandal over quality control. Subaru Corp. and Nissan Motor Co. revealed some of their vehicles had been inspected by unqualified workers, while Kobe Steel Ltd. and Mitsubishi Materials Corp. admitted to fabricating product data.

The machinery giant examined around 40,000 inspection records from the past two years after an on-site inspection by the transport ministry early this year identified malpractice.

IHI received a whistleblower report in April last year pointing to possible misconduct in inspecting airplane engines after routine repair and maintenance operations. But the company later concluded, in its own probe, that no misdeeds had been committed.

The transport ministry has ordered eight other companies in the industry to report by early April on whether they have found similar misconduct.