Question Author
My understanding was that as Universal put most of the money up for the BBC, they insisted the series had an American star (hence Robert Wagner).
The good old Beeb however said he would only appear after several episodes had been aired which would be historically accurate as Colditz had no Americans until after 1941 and Pearl Harbour.
Universal were still not happy and when they tried to show a pilot show on American TV ("Gone Away" as 1 episode), and it bombed.
Consequently they pulled the plug on it ever being released on video or DVD. A shame really as it was a first class and well acted series - best episode was "Tweedledum".
I managed to buy the DVDs on EBay, which was recorded from UK Gold, the only repeats in the Uk back in 1998.
Happy hunting
Bobby