The BBC dropped from its schedule this week an episode of classic documentary series The World at War which focuses on the Holocaust and concentration camps.
The 1970s series, produced by Sir Jeremy Isaacs, is currently being repeated on weekday afternoons on BBC Two.
On Monday, the 19th of 26 episodes was shown, featuring the Battle of the Bulge and Arnhem.
But Tuesday’s episode was number 21, focusing on the final invasion of Germany.
The missing episode, Genocide, looks at Nazi policy between 1941 and the end of the war.
It includes images from concentration camps, which the corporation said were “particularly distressing” and not suitable for a daytime audience. A spokesman insisted that the episode will be shown later this month after 11pm.
Viewer Peter Shaw has been following the series and said he was surprised when the episode did not appear as expected.
“The timing is really bad because we have recently had high profile cases with Holocaust deniers,” he said.
“The rest of the series is very distressing as it is. The episode about the mass bombing of Dresden has images of burning bodies in the streets, which is just as distressing as the pictures from the camps.
“I’m annoyed with the BBC’s decision and I think it’s a gross failure on their part not to show the episode in sequence.
“They could have just given a warning about its content at the start.”
Sir Jeremy Isaacs said he was unaware that the programme had not been shown, and added: “I rather regret this because I think people are not all that easily offended, but it is a particularly horrifying episode.”
But he added: “It is a matter for the BBC’s judgment.”
A BBC spokeswoman said: “Episode 20 in the current repeat of The World at War has not been omitted, but will be shown at 11.20pm on March 17. This episode includes some particularly distressing images which we decided weren’t suitable for a daytime audience.
“The continuity announcer will point to this episode after the one being shown at 2pm on March 11.”
She said the corporation takes the Holocaust seriously and had recently shown series on Anne Frank and Auschwitz.
There was no suggestion that it was “hiding” the Shoah, she added.
The World At War is considered the definitive television history of the Second World War, and ranked 19th in a list of the 100 Greatest British TV programmes in 2000.