JAPANESE AUTHORITIES have raided the headquarters of camera manufacturer Olympus as part of an investigation into dubious accounting practices.

Olympus is suspected to have concealed €1.15 billion in investment losses dating back to the 1990s.

The situation came to light when former president and CEO Michael Woolford informed the authorities last month. He was fired from his post in October after confronting the company’s directors, but remains a director in Olympus.

Earlier this month, the company managed to file five years of documents containing revised earnings reports with financial regulators within hours of a deadline to avoid removal from the Tokyo Stock Exchange.

Kyodo reports that prosecutors are working to build a case by March 2012 against former Olympus executives they suspect of leading the accounting fraud in a number of year-end financial reports. No one has been charged in the investigation.

In a statement released by the company’s current president and CEO Shuichi Takayama earlier this month, Olympus said it was committed to rebuilding its reputation and trust “by overhauling our management structure so as to meet society’s expectations”.

It also said that it intends to “take all necessary action against the responsible individuals”.

- Additional reporting by the AP