The Accuser (1977)

Original title: L'Imprécateur

In this sardonic comedy, after an executive is killed in a mysterious automobile accident, the French offices of his multinational company is inundated with mysteriously threatening be-ribboned anti-capitalist tracts, delivered overnight to everyone's desks. Later, the executive's body is brought to company offices for an official wake -- only no one at the company has ordered that such a thing be done. A mysterious prankster, who is able to imitate the voice of the company's president, has arranged these things. When Americans from the head office get wind of these developments, they institute a search for the perpetrator which leads to mysterious subterranean passages under the company's skyscraper.