Yes, there are quite a few. Mostly captured bikes being used ad-hoc by whoever captured them. A few pictures show them being in what looks like official use. I think a set of 'C' census numbers were set aside for such official use ?
Rich.
Not only that but I am aware of at least one BMW R.75 abandoned during the German retreat from France in 1944 was acquired as a trophy by a British Army Officer and shipped back to the UK for his own use. Collected by relatives at a south coast port it was kept under cover till he returned and was de-mobbed where upon it was moved to his house just outside Bromyard. I saw the machine in his garage around 1974.