Who were these POWs
 

It'd be too much to ask to identify exactly who these miserable POWs were but I wonder if anyone has ideas about the uniforms and in particular the soldier centre left? Does anyone recognise that uniform, the cap, the jacket with a very large collar and the diagonal buttons?

(This is an original photograph that I own)

Re: Who were these POWs
 

I do not think the front buttons are diagonal. I think there is a button just above the belt buckle (just above to the right of the metal part of the buckle).
The spot further to the right is not a button but a spot on the photo. There is a similar spot below it and slightly to the right, on the belt. The middle button on the jacket is buttoned but the "top" button is unbuttoned and is pulled to the left. That said, the jacket is unusual in that it does not have breast pockets and has a very wide collar. Do you have any idea where/when the photo was taken? Trying to think of unusual allied troops, one unit that comes to mind is the Brazilian Expeditionary Force (FEB) which operated in Italy.