I went over to Canada Water for a walk yesterday lunchtime and walked round Greenland Dock - on the way back to Canada Water tube station, I passed this under a bridge walking back to Surrey Quays Shopping Centre from the north-west corner of Greenland Dock - certainly, if it is not a 'Banksy', it is in his style...I have looked on-line, but not found anything definitive.

Regardless of it's authenticity, I like it - at first glance, from a distance, it looked like a real person...and the (real) discarded drinks can just adds to the effect...only getting closer did I realise that it was a painting.

[edit: 16/10/2017]

Adding a link to the Artsy website - lots of details about Banksy as well as many other artists...an incredible resource!