The Estonian prosecutor's office has opened criminal proceedings in connection with the Panamanian-registered tanker Probo Koala's attempt to unload slops suspected of toxic content and the ship was prevented from leaving the port of Paldiski by the central criminal police. Test results of samples taken from the slops indicated the presence of toxic chemicals and the prosecutor's office opened a criminal case at the Environment Ministry's request, vice chancellor Allan Gromov said. In connection with the legal action, the prosecutor's office dispatched officers of the central criminal police to the ship today to prevent it from leaving Estonian waters. The tanker will remain in the port of Paldiski as long as necessary for the inquiry, the prosecutor's office said. The environmental pressure group Greenpeace has asked Estonia to impound the ship and a corresponding request was made by the commission conducting a probe in Ivory Coast after several deaths from exposure to toxic waste discharged by the vessel in the West African country last month.