LOST keys have landed prison bosses with a five-figure bill after a staff slip-up prompted hundreds of locks to be replaced.
Figures released to the Evening Mail following a freedom of information request have shown a single set of keys lost at HMP Haverigg in May has set the jail back £30,450.
The lost keys, which were later recovered, prompted the jail to change 410 locks and issue 500 new keys as a security precaution.