A spokeswoman for prosecutors in the western German city of Essen said they had received a complaint concerning Brenntag from three non-governmental organisations - New York's Open Society Justice Initiative, Berlin's Syrian Archive and Switzerland's Trial International.

"The complaint is being checked. We haven't yet decided whether to launch an investigations," the spokeswoman said.

Shares in Brenntag dropped after the report and were down 7.45% at 0853 GMT.

(Reporting by Matthias Inverardi; Writing by Michelle Martin; Editing by Ludwig Burger)