Dismissing legitimate criticism in this way draws an imaginary distinction between wholesome, democratic Britain (where torture just doesn't happen) and evil "police states", located far away in the Third World. Whilst such abuses are certainly less frequent here, for which I am profoundly thankful, the difference is one of degree and not of kind. To lose a family member in violent circumstances is no less unbearable in Britain than anywhere else.
Finally, your rejection of the criticism of rising British prison populations - "patently a matter of domestic criminal justice policy" - is chillingly identical with the excuses used by torturing states throughout the world. If British prison policies are defensible, we have every responsibility to do exactly that - and defend them, instead of placing ourselves arrogantly above the "international morality" that we are so quick to enforce on other states.