What are the laws in the uk regarding unpaid rent to a landlord?

I own a house which I rent out to tenants. They stopped
paying the rent about 3 months ago and when I went to the house i discovered they had left the house and later found they had left the country. I also found various bills for different credit cards which they had used to buy a number of laptops , phones, and other electronic items. They have also failed to pay gas and electric bills for the past 3 months. One of the tenants is still in the country but he says that he paid his share of the rent to the other tenants to pay to me. He does not have any credit cards to pay off as far as I am aware. This man is also the brother of one of the people who have left the country but he says he didn’t know they left until 2 days after. Am I able to hold him liable to pay the rent that is owed to me? Am I liable for any of the bills that are coming to the house. They are not in my name.