plowens

When I was About 10 years old I watched a film made in the late 40s - early 50s which was about a german-jewish father and son who come to live in an English community during the second world war. The young German-jewish boy makes freinds with an english boy called John but has less success bonding with Johns other freinds, as they regard him as a nazi because he is german, when in actual fact he and his father were persecuted as jews.
The film concludes with a mock firing squad execution which goes tragically wrong and ends in the death of the young german boy.
I've been trying to find the name of this film for so long that I'm begining to think that I must have dreamt it.

Please help