Ross Kemp is stripped naked for new TV series which sees him locked up in prison

When TV Magazine meets Ross Kemp, he’s exhausted, emotional and elated.

Just two days earlier, he and his wife Renee brought their newborn twin girls, Ava and Kitty, home from hospital.

“I’m tired,” he says with a huge grin on his face.

“But not as tired as my wife. It’s all going well, though my two-and-a-half-year-old son [Leo] has got chicken pox.

"We started off keeping him away from the babies, but he’s missed his mum for five days and he’s ill, so it’s not great. And of course, the more we keep him away, the more he’s going to resent the twins.

He’s going to resent them anyway, because he’s had sole attention for two years. He’s turned into a little monster since they turned up – for two reasons! – but he’ll get over it. He’ll have to!”

With his mind and schedule very full of family right now, it’s amazing that Ross has the energy – and time – to talk to us about his new documentary for ITV, Ross Kemp

Behind Bars – Inside Barlinnie.

But it’s a subject matter he’s passionate about.

“We are very lucky in this country, but that’s not to say there aren’t some serious things we need to look at, and I think the prison system is one of them,” reasons Ross, 53, who immersed himself in prison life at the notorious HMP Barlinnie in Glasgow for the film.

“I wanted to find out whether prisons work, whether they are here to punish or rehabilitate us, or are they just here to keep people we don’t want on the streets off them.

“I went through the admission system like an inmate – I got stripped naked and they all got to look at me. Lucky them! It was humiliating, but that system is there for a reason – to protect inmates and prison officers. Some of the things they have found being smuggled in don’t bear thinking about. They found three mobile phones in the anal cavity of one inmate, which was a prison record.”

Ross discovered that both phones and drugs are worth a fortune among prisoners inside Barlinnie, and was amazed by some of the lengths inmates go to in order to smuggle contraband into the facility.

“The drug issue is spiralling out of control, particularly with new psychoactive substances,” he says.

“I was told that people soak underwear in liquid Valium, dry it, then send it to the prisoner, who makes it wet again, wrings it out and sells it. Some even get their kids to paint a picture and send it to Dad – the sky is Valium, sprayed on, so they cut it up and sell it.”

Ross was also taken on a tour of Barlinnie’s E Hall, which houses sex offenders. As a father of four young children (as well as Ava, Kitty and Leo, Ross has a six-year-old son, Oliver, from a previous relationship), it was a gut-wrenching experience for him.

“It’s a creepy place, there’s a totally different atmosphere,” he recalls. “It is the same as the other wings architecturally, but it feels different, it smells different and it sounds different.

“In the other blocks, there’s shouting, there’s kicking of doors, but in E Hall there was silence, whispers, classical music being played in certain cells, it’s just really creepy. Maybe it’s because you know what’s behind those doors.

“I spoke to one offender who feels he has been rehabilitated, but says his attraction to children will never go. The job of a documentary maker is to present you with the facts and allow you to make your own mind up, but it’s very difficult to be objective in front of somebody who believes downloading sexual images of children is normal and that kids enjoy having sex on camera.

“But one of the biggest things I learnt was that you’re not going to change a person who doesn’t want to change.”

Ross hopes to work with ITV on more documentaries, a field he has made his own since making the move from acting some 13 years ago. And there’s one subject he’d still love to cover – US President Donald Trump.

“I find it incredibly fulfilling to travel the world, meet interesting people and interview them,” he says.

“My dream, if money were no object, and twins and family permitting, is to spend a year in the Oval Office. I’m fascinated by human beings and what makes us tick.”

NEW! Ross Kemp Behind Bars: Inside Barlinnie Thursday 9pm ITV