Former International Monetary Fund chief Dominique Strauss-Kahn is being questioned by French police for his alleged involvement in a prostitution ring. Police have questioned several prostitutes who had reported having sex with Strauss-Kahn, who resigned from the IMF in May after he was charged with the attempted rape of a hotel maid in New York City. The case was later dropped. Strauss-Kahn said he did not know the women were prostitutes.