Japanese endoscope manufacturer Olympus Corp said on Monday it has sacked Chief Executive Stefan Kaufmann after an allegation that he had purchased illegal drugs, sending its shares sliding 6%.

Olympus, which has called Upper Saucon Township home since 2006, said it received FDA 510(k) clearance for two scopes: the GIF-EZ1500 gastroscope and the CF-EZ1500DL/I colonoscope.