The majority of cases where goods have been left at the property by a tenant are when the tenancy has been abandoned. You should consult this guidance for details on abandoned tenancies. This guidance assumes there is no question as to whether the tenant has left or not. It purely deals with the situation that the tenant has gone (either via abandonment, court order or surrender).
When one party (the bailor) leaves his goods in the possession of another (the bailee) a legal relationship called ‘bailment’ arises automatically. Unless appropriate steps are taken, there will be an obligation on the bailee to return these goods at a later date and the bailee can be held liable for any loss or damage which occurs to the goods whilst in the care of the bailee. [Torts (Interference with Goods) Act 1977] & [Toor v Bassi  EGCS 9]