Investigative journalist Paul Connolly has been spending time in some of the world’s strictest prisons, home to some of the most dangerous people on the planet.

In the first of a three part series, Connolly spent five days inside purpose-built Polish prison Piotrkow – a maximum security prison where some inmates serve as many as 23 hours a day in isolation so they don’t form any dangerous alliances with others.

And viewers couldn’t believe just how tough things were in there.

The experience seemed to genuinely shock Connolly – who at one point was reduced to tears after being roughly handcuffed and dragged and locked in a tiny room.

paul connolly crying on the show after spending time in isolation
(Screengrab/Channel 5)

It proved to be quite an eye opener to many, and definitely got them thinking about the way UK prisons are run.

David Cameron will have a mention next time he checks his Twitter…

Overall people seemed to really like it.

(…the show, not the prison. They certainly don’t ever want to end up in a place like that with guards that do THAT.)

guards using a shield against reporter connolley
(Channel 5)