Olympus said on Tuesday it had discovered that funds related to its acquisition of British medical equipment maker Gyrus in 2008 and three domestic acquisitions were used to cover losses on securities investments dating back to the 1990s.

The acquisitions are at the centre of a high-profile governance scandal that followed the dismissal of its British CEO Michael Woodford and has cut the market value of the camera and endoscope maker by more than half. (Reporting by Edmund Klamann and Chikafumi Hodo; Editing by Michael Watson)