An executive of a financial advisory firm for Olympus Corp. compiled false price estimates related to the acquisition of British medical equipment maker Gyrus Group PLC, which was used to cover up the Japanese company's past investment losses, sources said Tuesday.

The executive, a former Nomura Securities Co. employee, apparently compiled the false estimates to make up for Olympus' past securities investment losses by inflating the value of Gyrus' preference shares.

A third-party panel set up by the camera and medical equipment maker is probing whether former Olympus President and Chairman Tsuyoshi Kikukawa and board members were fully aware of the falsification, the sources said.