Developer Grantside said staff were clearing asbestos from the site before securing the listed buildings and demolishing the other parts of the factory.
She said she had been "shocked to discover" that in Portavogie, County Down, the council found itself powerless to enforce a public health notice for clearing asbestos on a site where the developer was in administration, despite reports that children played there.
Meanwhile, the grim task of clearing the wreckage from the site of the Paddington disaster continued on Monday morning with teams beginning to remove more carriages from the scene.