Large metallic blue bodied clear winged insect - London, UK (1 Viewer)

Hello, about the size and dimensions of a hummingbird hawk moth (colours completely different) but may have been a fly or beetle. Much bigger than bees and blue bottles, certainly with its wings added. Attracted to Rowan blossom and was at the top of the tree but flewoff narrowly evading attention of a landing sparrow. Body was metallic blue in the light and wings looked clear. Looked heavy bodied. Not long or elegant enough to be a demoiselle.

Any ideas ?

An option?

https://www.google.com/search?ei=ML...MC43mAEAoAEBqgEHZ3dzLXdpergBAg&sclient=psy-ab

The wings are very dark, so probably not Xylocopa, although that was my first thought.

Based on videos I have now checked that looks very close indeed. There is a chance light can change how it appears when flying.

The other option I considered was cockchafer but I have read this doesn't fly so well so ruled it out.

Thanks for your suggestion. I believe you are both right. If I see it return will try to get a picture although it was quite quick when it wanted to be.

Stunning looking creature !