Prosecutors in Japan have raided the Tokyo headquarters of Olympus, which is under investigation for hiding huge losses.
Twenty other premises were searched as well on Wednesday.
Olympus is being probed over its accounting practices and the admission that it hid losses.
The issue came to light after former chief executive Michael Woodford was fired for questioning payments relating to mergers.
Olympus admitted that it hid $US1.5 billion in losses over the past two decades.
Last week Olympus filed revised earning reports for the past five years with the Tokyo Stock Exchange.
In its latest accounts for the six months to the end of September the camera company declared a loss of 32.3 billion yen ($US414 million).
It also revised the value of its net assets to 46 billion yen, down from the 225 billion yen stated in March 2007.
Olympus shares closed 1.4% lower at 1,050 yen.
Analysts said the raid on its headquarters just days after the filing of the report was a significant development.
The BBC reports the developments at Olympus have raised concerns about corporate governance in Japan.