Question

why do you think there is a rule that confussions made during police custody cannot be used as evidence against the accused?

Answer 1

I can’t think why you would think that in the UK, as you would be entirely wrong.

Confessions made to the police are completely admissible and, given the way in which they are recorded and the way in which conditions of detention are controlled and monitored, they are now only rarely challenged by the defence.