A factory trawler packed with polystyrene containers and fuel is still on fire a week after it caught alight in Cape Town harbour, but the cause of the blaze remains a mystery. The Russian-registered Verano is proving a major headache, largely due to toxic fumes billowing from the fire inside the vessel's fish holds.The boat, now listing to one side, is being closely monitored by Transnet, the South African Maritime Safety Authority and salvors appointed by the vessel's owners.Oil booms have been deployed to prevent fuel pollution, maritime authorities said yesterday."Samsa is maintaining a close eye on the process and will conduct an internal investigation when it is safe to do so," the statement said.Five crew members were safely evacuated on Wednesday last week. The berthed ship is under round-the-clock surveillance.Veteran maritime commentator Terry Hutson said the fire could have been caused by an electrical fault. "When fires like this do occur they are often put out very quickly," he said.Transnet last week confirmed the vessel was carrying 150kl of fuel and 800,000 pieces of plastic packaging material. The plan was to debunker the fuel as soon as possible. ..