I spotted this little critter on the banks of the River Mersey and just as was I photographing it two walkers happened to be passing by and we had a discussion as to what it was. I said a white mink, as did one of the walkers whereas the other couldn't decide if it was a polecat or a ferret.
I believe it to be a white mink, however I am far from an expert on minks, but one thing I do know is that minks are good swimmers and this creature was a brilliant swimmer. It would slip into the murky water and disappear out of sight and fifteen seconds later it would surface in a different location. It is also a hunter as we witnessed when it very nearly captured a moor-hen.
Can anyone give a positive id as to what it is? (click on each image to enlarge)