Diplomats working to find Aiden Aslin, who was forced to surrender to Russian troops with his unit in Mariupol
A British man fighting alongside the Ukrainians has been captured and beaten by pro-Russian forces, his family fear.
Aiden Aslin, who is from Newark in Nottinghamshire and has been fighting in the besieged city of Mariupol, was forced to surrender with his comrades earlier this week after they ran out of food and ammunition.