The wartime diary of Anne Frank has been found to contain a script for the pilot episode of Mrs. Brown’s Boys.

Recent imaging analysis of the diary, which was maintained by the Jewish teenager from 1942 to 1944, revealed that several pages had been pasted over to hide their contents. When researchers looked closer, they found a collection of bawdy, tasteless and unoriginal jokes that they instantly recognised as coming from the mystifyingly successful BBC sitcom.

“The ‘jokes’ were outdated even for the 1940’s and we realised straight away the true horror of what we had discovered,” said lead researcher, Jan Bakker.

Whilst it is still not clear if the script was written by Anne herself or by a family member with access to her diary, Bakker said that they were a good indication of how stressful the Franks’ situation had become.

“Anne often described how tensions had built up within the safe house, and it’s not unusual to deal with such situations by resorting to gallows humour,” he explained.

“The fact that somebody went beyond that stage and into the absolute drivel that is Mrs. Brown’s Boys suggests that things were very grim indeed.

“They at least recognised the horror of what they had created and had the decency to try to cover it up, though one can only speculate as to why they didn’t resort to killing it with fire so that it could never be discovered.”

At present, it is unclear how the script came to fall into the hands of the BBC in 2011, though Bakker has suggested that it may have been copied by the Gestapo when they raided the safe house and then covered over, so that it could be weaponised at a later date.

“It’s not unusual for World War 2 weapons to end up in people’s lofts, so it’s entirely possible the copy was discovered years later when somebody was cleaning out their grandfather’s collection of Nazi memorabilia.

“And to think, up this point everyone thought that the most horrifying thing to come out of the World War 2 arms race was the nuclear bomb.”

At press time, there are reports that the diary has been destroyed by controlled explosion, after Bakker’s team discovered what appears to be the draft script for a special Mothers’ Day episode.