Is this a bee fly?

I have been told that this is a bee fly, a member of the Bombyliidae family but after looking at hundreds of pictures on the internet I am not so sure. There are 5,200 species of flies in the UK. I guess this one’s wingspan was about a centimetre and docile enough to enable me to get up close for the photo. Any help in identification appreciated.

I have been at Thompson’s Rigg, a National Trust property which contains Blakey Topping installing fencing around enclosures along Crosscliff Beck for the water voles. That is not to keep the water voles in but to keep the marauding sheep out encouraging streamside vegetation growth.

Edit: the Giant Tachinid Fly, Tachina Grossa, apparently.