Ryan Lock, 20, who is said to have no military experience, has been reported dead by Kurdish activists, according to the BBC.
In the report it states Mr Lock travelled to join Kurdish forces known as the YPG in August and was killed on December 21 in the battle for the Syrian city of Raqqa.
Mr Lock was described as ‘a very caring and loving boy’ in a statement by his father John Lock.
A spokesperson Foreign and Commonwealth Office: “The UK has advised for some time against all travel to Syria. As all UK consular services there are suspended, it is extremely difficult to confirm the status and whereabouts of British Nationals in Syria. Anyone who does travel to these areas, for whatever reason, is putting themselves in considerable danger.”