Four people have been arrested during a sting operation for allegedly staging an elaborate hoax involving the exchange of pieces of white paper for euro banknotes, Thessaloniki police said yesterday. The suspects – two Nigerians, a Cameroonian and a Frenchman, between the ages of 26 and 31 – allegedly told prospective victims they had fled an African state with 2.8 million euros in banknotes, which they had covered with a special white liquid. This coating, they claimed, could only be removed with the use of chemicals and actual banknotes in a sort of printing process. The suspects were arrested after displaying how they would manufacture the money to a plain-clothes officer and arranging to take 300,000 euros from him in exchange for returning double the amount. Officers are investigating claims the men used the same scam to swindle a Kavala storeowner out of 180,000 euros.