A criminal case has been opened in Antwerp Criminal Court against three Belgian companies that allegedly sent 96 tons of isopropanol, a precursor to the chemical weapon sarin, to Syria between 2014 and 2016, according to a Bellingcat investigation. Belgian authorities say the companies in question did not submit “appropriate permits” to customs officials, and the “established facts were the subject of a criminal investigation.” The prosecution began in late March, the citizen-journalist watchdog site reported. AAE Chemie, Anex Customs, and Danmar Logistics have all said they were “not aware that export licenses were compulsory for exports of chemicals to Syria,” and claim they have been going without licenses for more than a decade. They also say Belgian customs officials “never refused any of the exports.” The customs office says it only realized the licenses were not submitted after the shipments were already exported. The opening session of the case is scheduled for May 15.