The series was a huge success in the 1980s

The documentary, I Have a Cunning Plan: 20 Years of Blackadder, was due to air on Tuesday but was replaced by a programme about the musical Singing in the Rain.

A BBC spokeswoman said: "Radio 4 was unable to broadcast I Have a Cunning Plan because of contractual matters.

"We are trying to clarify these and expect to be able to broadcast the programme once this process is completed."

The historical comedy was a huge success for the BBC in the 1980s, starring Rowan Atkinson in the lead role and Tony Robinson as his sidekick Baldrick.

The last series took a more serious tone

Curtis and Elton wrote three of the four Blackadder series between them. The first series was written by Curtis and Atkinson.

Blackadder returned for a one-off special in 1999, which was shown at the Millennium Dome in London before being screened on Sky One.

The popular character also appeared in a trailer promoting concerts in Buckingham Palace gardens for the BBC's Music Live festival marking the Queen's Golden Jubilee last year.

Curtis also scripted comedy sketch show Not The Nine O'Clock News and Mr Bean, which made Atkinson a household name.

The pair are now as famous for their film credits as their television work.

Curtis's work includes British box office smashes Four Weddings And A Funeral and Notting Hill.

Atkinson recently appeared in spy spoof Johnny English.