Tenant's belongings

Other

My tenant had not paid rent and appeared not to be living in the flat for some months before obtaining possession of the flat through the court. Sometime before I applied to the court and in response to a phone call I made to his employer (he had not responded to any notes I had left at the flat or texts I had sent)he did text me saying that he had been unwell and was still living in the flat. I gave him the benefit of the doubt but there were no more communications from him and his flat appeared unlived in so I applied to obtain possession of the flat. This I duly received and, on my agent's advice, had the flat emptied and I have stored his possessions. How long do I have to keep them for?