THE Chinese insurers of the burned-out casino ship New Orient Princess are refusing to pay compensation because they say they did not know the vessel was to be used for gambling. Lawyers for the ship's Hong Kong-based owners are mounting civil court action to contest the non-payment of an estimated $20 million by the People's Insurance Corporation of China. Mike Stevens, of law firm Holman and Fenwick, said he did not know why the company was refusing to pay out. Sources close to the owners said it was believed the insurers were preparing a defence that they would not have insured the ship if they had known what it was used for. A Fire Services Department investigation found that the most probable cause for the fire was a wiring fault in the ship's sauna. The 25-year-old Panamanian-registered ship caught fire in late August shortly after leaving Kowloon Bay on a regular overnight gambling excursion into international waters. A three-day fire gutted the 4,600-tonne ship and left it a write-off. The wreck is beached at Tseung Kwan O despite requests by the Marine Department for its owners, a collection of Hong Kong gamblers, to remove it by December 8.