ULTIMATE FORCE, ITV1, Sunday 9pm

IT would be fair to say that super soldier Henno Garvie is rather hard. With muscles like a sack of footballs, he doesn't even need to shoot people – he simply throws them at a stationary bullet at over 200mph.

Expertly brought to life by Ross Kemp in a role he was born to play, Sergeant Garvey is the heart and soul of Ultimate Force, which returns to the screens after a long mid-season break.

Intelligent, unflappable and brave, Henno heads up Red Troop. An SAS trooper for 15 years, he has served in the Gulf, Falklands and Northern Ireland. The Regiment is his great love – and he puts it before anything else in his life.

Thanks to Kemp, a character that could be one-dimensional actually becomes a fascinatingly multi-layered individual, trying to do his duty in a changing world.

Kemp is certainly still fond of the no-nonsense soldier, and that's got to be good news for Garvie's army of fans. And the well-known former soap star admits that he'd struggle to keep up with him one on one.

"I'm a scaredy cat," he laughs, when asked if he could imagine being a soldier for real. "I've got lots of friends who are soldiers and I admire them and thank them for protecting my way of life. But I'd never have made a good soldier myself. What we are trying to do is thank them by presenting them in a hopefully good light.

"I'm very proud of the series, what we achieve and how we get away with it in the locations that we have. Having spent a bit of time in East Africa, I never thought we'd get away with filming Africa in Oxfordshire but we did.

"Instead of the Amazon, we got 12 heavily armed people with blackened out faces into a speedboat just around the corner from Windsor Castle. There would have been a major security alert if we'd gone round the next bend."

This fourth series, which returns after a break, sees Ross getting close to the action once again. His stunts include jumping off a building on to an open-top bus, while a lorry-load of fireworks explodes nearby.

"The amount of pyrotechnics we get through is amazing," he says. "Before half past 11 on one Friday I had blown up a helicopter and taken out a cocaine factory. We were very close to the explosion and it was one take with rounds firing and rocket launchers going," he says.

"Hopefully the more you do something, the better you get. Sometimes it means more corners are cut. I don't think we've done that – I think Bentley is spending more money."

Before filming the series, Ross spent three months in Brazil, New Zealand and Los Angeles making a documentary series on gangs for Sky. He realised he's become a somewhat unwilling expert on weapons.