TV presenter Richard Madeley has visited the world's toughest prison in El Salvador where 3,000 shaven-headed inmates are crammed behind floor-to-ceiling bars with nothing to do.

TV presenter Richard Madeley has visited the world's toughest prison in El Salvador where 3,000 shaven-headed inmates are crammed behind floor-to-ceiling bars with nothing to do.

The Good Morning Britain presenter is giving a glimpse inside one of the world's most controversial prisons.