Probably stocked looking at the size of it and those mown banks , cracking condition Cock fish all the same. Saying that browns it waters that have Crayfish can grow big.
Good to see you returned it, maybe good to the breeding population.
It was a good job you were trout fishing coarse fishing season doesn't start for a few days.
Just a heads up, make sure you always have the appropriate rod licence, because if you are somewhere you are not meant to be, not having a rod licence is the biggest thing you can get nicked for.
rod licence?... Lol
Not lol pal, up to £2000 fine if you g