Advice please re: white goods left at end of tenancy

Other

My overseas tenant left the property in June 2011 at the end of his tenancy and returned to his home country the following day. All was in order except that during his tenancy he had installed a washing machine into the property which he asked me to buy from him (this conversation took place in the last week of his tenancy). I did not want to do this so declined his offer. He then decided to offer it to the incoming tenant but as no new tenant had been identified by the time he left he was unable to do this. He therefore left the property with the washing machine in situ. The property has now been relet by a letting agent to a new tenant whom I have yet to meet. The original tenant rang me this afternoon to ask about the washing machine which he now wants to reposess or sell to the new tenant. He intends to visit the property tomorrow to do this. The other complication is that prior to him leaving the outgoing tenant gave me the guarantee for the washing machine and the receipt showing the purchase. These documents clearly show that the machine was bought on a credit agreement which has 2 more years to run. Any advice on what to do next would be welcome. Thanks