Robbie Coltrane talks about his hard-hitting new three-part thiller, Murderland, screening on ITV1 on Monday, October 19…

So we hear you have been based in a London school playground while filming. Have you met any of the children?
“They don’t know luckily. Christ, if word got round! Usually they go all doe-eyed, it’s really sweet actually. I am so used to playing baddies and serial killers and then suddenly it’s, ‘My mummy says you play Hagrid in Harry Potter’?”

This is your first TV for a while?
“I said to the writer David Pirie, ‘Why doesn’t anyone write really good drama that is totally engaging, where everyone isn’t 25 and gorgeous?’ The whole vroom-vroom stuff – like CSI – I can’t watch that. You will have to work hard to watch this, it’s not something that you can sit back and let flow over you – it’s not Sunday night fluff.”

So it has been a tough shoot?
“Very harsh. We’re doing six days and most are 12-14 hours. I never really get to my trailer because I am on set the whole time. Because it’s three different views, it’s three times the work, but I’m loving it. There are lots and lots of flashbacks and they are different points of view, so it is not just one person’s story. You really don’t know what to believe at any one time. At the end of the first episode you think one thing, then another at the end of two and then at the end of three you realise it is none of the things you imagined!”

As you’re playing a policeman do you think there will be comparisons with Cracker?
“Well, we are trying to make sure there aren’t, because it isn’t anything like it. It is nothing to do with psychology or having a psychological insight it’s more about personal involvement. There is a psychologist [played by Mistresses star Sharon Small] in this who my character hates, which is funny and quite ironic really.”

Will this mean we will be seeing more of you on telly from now on?
“If the show was like this I would do it tomorrow!”