TOKYO (Reuters) - Japan's Subaru Corp falsified mileage and emissions readings on hundreds of vehicles, the country's national broadcaster NHK reported on Thursday, knocking off as much as 3 percent from Subaru's share price.

The alleged misconduct, if proved true, could deal another blow to the automaker which admitted an inspection scandal last year.

Subaru, Japan's sixth-largest automaker, provided readings for its popular Forester compact SUV and other models produced at one of its domestic plants to the country's transport ministry which were inconsistent with in-house figures, NHK said, without citing sources.

Subaru said the report was not based on information provided by the company.

The automaker had said it was investigating the matter, and would file a final report to the transport ministry by the end of March. But a transport ministry official said on Thursday that it was yet to receive the report.

The latest revelation follows Subaru's admission in October that uncertified staff had been for decades carrying out final checks on new cars sold in the domestic market.

Mileage readings, an indicator of fuel efficiency, do not fall under safety requirements. However, any proof of what would be a second instance of misconduct in the past year would taint the image of not only Subaru but also Japan's manufacturing industry that has been rocked by a slew of scandals recently.

(Reporting by Naomi Tajitsu and Maki Shiraki; Editing by Gopakumar Warrier)