Biographer and cultural historian Graham McCann has revealed details of a long-forgotten, aborted sitcom pilot that would have starred Morecambe & Wise.

At the height of their fame in the early 1970s, the hugely successful comedy duo were in talks with the BBC about starring in their own sitcom, and a pilot script was commissioned from writer Roy Clarke, whose Open All Hours and Last Of The Summer Wine pilot episodes had both recently been broadcast.

McCann discovered details of the commission in 2014 whilst researching at the BBC Written Archives Centre for his book, Still Open All Hours

Speaking to British Comedy Guide today, he explained: "I was looking through papers relating to Roy Clarke and, in-between other things about Open All Hours and Last Of The Summer Wine was a memo from Duncan Wood, Clarke's great patron at the BBC, about this pilot."

Wood, then the Head of Comedy at the corporation, wrote to a colleague: "Would you please commission Roy Clarke to write a single 30-minute situation-comedy pilot script for Morecambe and Wise on the broad lines as discussed between Roy Clarke, H.L.E.G. Tel. [Head of Light Entertainment, Bill Cotton], and myself at our meeting today. Roy Clarke has agreed to accept the commission with a delivery date for the script of 1st June, 1973."

Famously devoted to his craft, the memo was dated 10th May - giving Clarke just 21 days to write the script.

Graham elaborates: "However, when I phoned up Roy Clarke to ask him about it, he refused any knowledge of it, either the meeting or of having written such a script. He is a big fan of Morecambe & Wise so was adamant he wouldn't have forgotten!"

Finding only one single further mention of the pilot, referring to it as 'Project no. 011430190' and detailing that Clarke would be paid £800 (an above-average fee at the time), McCann believes the sitcom was aborted before going much further.

"If there was a script, it would have been there with the other papers," he explained. "I suspect that once they got wind that this was seriously happening, Morecambe & Wise - Eric, in particular - pulled the plug on the idea. He was probably, not panicked, but aware of the stakes involved. They'd already had the notorious failure of their first TV series, 1954's Running Wild.

"They always wanted to move into narrative comedy, aspiring to film success and of course eventually moved to Thames in the late 1970s to try just that, but at this point already had very little time in between making their hit BBC series and the Christmas specials. Roy Clarke, too, would have been busy with both Last Of The Summer Wine and Open All Hours commissioned to series."

He adds: "I think, also, Duncan Wood's departure for Yorkshire Television a few months later probably didn't help. He might have pushed the project again, but James Gilbert who replaced him as Head of Comedy was, at that particular time, a greater proponent of sketch comedy like The Two Ronnies, and was already formally committed to developing sitcoms for Barker and Corbett as part of their own deal."

Graham McCann also notes that the flat sketches within The Morecambe & Wise Show provided much of what a sitcom may have done. He says: "You could almost have strung those together and had a sitcom. But it's tantalising to imagine, given Clarke's fabulous dialogue, what this pilot could have become."

Writing an account on website Chortle, he concludes: "As for the mystery of the missing sitcom: well, as Eric would have said, there's no answer to that. We may as well just savour the wonderful shows that we have."

Graham McCann's books Still Open All Hours and Morecambe & Wise are available now.