As luck would have it I bumped into Martin Mathias who had seen it and taken this photo. Apparently it was sadly killed in a collision with some vessel.
I have seen hundreds of Risso's over the years but never one so close up so it was interesting to see his pic' and also the teeth which i had never seen before. Interestingly although some books say thwey have no teeth in the upper jaw this one does appear to as does the one I found on the internet!
Thanks Martin!