The actor plays John Martin in the series, based on a true story of a US paratroop unit during the D-Day landings.

He stars alongside Friends' star David Schwimmer, Marc Warren and Damian Lewis.

Dexter says that playing a part in a war series on television is nothing like fighting in a real war.

He told Teletext the real John Martin is now 80, and that "playing John was a humbling experience. He'd been through so much.

"He'd been through this amazing war. He still finds it hard to come to terms with seeing soldiers of 18 and 20 dying in front of him."

Dexter adds that he spent 10 days in an American-style boot camp to perfect his performance.

"We did 5km runs, orienteering, square-bashing, weapons training and calisthenics," he says.

"It was pretty tough as I wasn't fit before I did it, but I enjoyed it. It was a unique experience."

Band of Brothers will be shown on BBC2 in the autumn. It is directed by Tom Hanks and Steven Spielberg.