Hino’s troubles with emissions data falsifications appear to have escalated, with the company announcing in Tokyo on Monday, that it will suspend shipments of light duty trucks, after confirming that the data falsification scandal also included those models, highlighting the deepening problems at the Toyota subsidiary.

Hino president Satoshi Ogiso told a news conference that during a transport ministry investigation additional misconduct regarding emissions was found that affects more than 76,000 vehicles.

The scandal, which came to light in March, was previously not believed to have impacted light duty trucks,  a factor which saw Hino shares lose about 3.5 pert cent on Nikkei, with parent Toyota’s shares losing 0.5 per cent on Monday. Hino is 50.1 per cent owned by Toyota and the scandal has rocked both organisations from all reports.

“We are extremely disappointed that Hino again betrayed the expectations and trust of its stakeholders,” Toyota president Akio Toyoda said in a statement.

Hino said in its statement that 76,694 vehicles of its Dutro/300 Serries light duty models were impacted, bringing the total number of vehicles involved in the scandal to more than 640,000.

The truck maker said even though the engine for the small trucks was supposed to be tested at least two times at each measurement point, it only tested once at each site.

The latest shipment stoppage means that Hino will be pausing shipment of 60 per cent of its vehicles for the year, a spokesperson said. It will continue to ship its small Dutro 1.5 tonne models, since Toyota makes its engines, the spokesperson added.

Hino boss Satoshi Ogiso said the company was checking the impact to earnings from the additional misconduct, adding that it had not found instances of vehicles exceeding emissions limits and the misconduct was due to lack of understanding of regulations.

“As an automobile manufacturer, it is absolutely necessary for us to have a thorough understanding of the rules and regulations in order to release vehicles,” Ogiso said. “I have explained that (the misconduct) was unintentional, but I have no intention of saying that because it was unintentional, it is OK.”

He went on to say that it was “indefensible” that the additional falsification was unearthed by the transport ministry, not the company nor its special investigation committee set up to investigate the whole issue.

Hino blamed an inward-looking corporate culture and a management failure to engage sufficiently with workers that led to an environment that put greater priority on achieving schedules and numerical targets than following processes.

The truck maker also falsely reported to the transport ministry there were no improper incidents in emissions and fuel efficiency tests at the time of receiving certification in 2016, following the revelation of Mitsubishi Motors Corp’s mileage cheating scandal.