Olympus ex-chairman Tsuyoshi Kikukawa and six of its executives have been charged by Tokyo prosecutors in connection with a $1.7 billion accounting cover-up.

Tsuyoshi Kikukawa, executive vice-president Hisashi Mori and former auditor Hideo Yamada are among those charged with falsifying securities reports, according to Reuters and Bloomberg news agencies.

Olympus ex-chairman Tsuyoshi Kikukawa and six of its executives have been charged by Tokyo prosecutors in connection with a $1.7 billion accounting cover-up

The three were arrested last month.

Olympus case has become one of Japan’s biggest corporate scandals.