The episodes, from Series 2 of the show, are currently missing believed wiped and thus haven't been seen on television since 1969.
Gold has ordered the remakes as part of its celebrations of the sitcom's 50th anniversary. The first episode of the Home Guard focused comedy, by Jimmy Perry and David Croft, was broadcast in July 1968, and the three new re-recordings will be aired to mark their own 50th anniversary, in 2019.
Dad's Army Series 2, which was broadcast in March and April 1969, featured six episodes. The three episodes were lost as a consequence of the BBC's contemporary cost saving policy of wiping and reusing expensive video tape. Contracts allowed for only one repeat broadcast of each episode, and there was no foresight to future value in the programmes.
The first two episodes from the second series - Operation Kilt and The Battle Of Godfrey's Cottage - were believed lost, but in 2001 copies were discovered as part of the corporation's 'Treasure Hunt' drive. Episode 4 - Sgt. Wilson's Little Secret - is the only episode from the series for which a good copy exists. It is next due to be repeated on Gold on Monday 1st October.
Episode 3 (originally broadcast on 15th March 1969) - The Loneliness Of The Long-Distance Walker - is one of those missing. It focuses on Walker receiving his call-up papers for the regular Army. Whilst Mainwaring's concerned about losing one of his few able-bodied men, Wilson is more concerned about his cigarette supplies.
An audio recording taken from the TV broadcast of Episode 5 (29th March) - A Stripe For Frazer - exists, but the visuals are still lost. In 2016 the BBC animated this audio, with the subsequent episode made available via the now defunct BBC Store.
Series 2, Episode 6 (5th April) - titled Under Fire - is the final missing episode from the series. It sees Frazer spotting someone signalling to the enemy. The suspect claims he is innocent, despite his German-sounding accent and the fact his dog is called "Fritz".
Episodes 3, 5 and 6 are included on the sitcom's combined Series 1 & 2 DVD release in the form of the audio from later radio re-recordings of the scripts, which featured the original cast.
Also missing are two short Christmas specials, running to around 10 minutes in duration each. Present Arms was broadcast at the end of Series 1, whilst The Cornish Floral Dance came after Series 4. Both were aired as part of the festive extravaganza Christmas Night With The Stars in their respective years, and only survive as home-made audio soundtrack recordings, also included on the existing DVD releases.
The new versions of the Series 2 episodes are being made by Mercury Productions. They will follow from the channel's new Alexander Armstrong-fronted documentary series Saluting Dad's Army, looking at the history of the programme, which is currently scheduled for broadcast next month.
It is not yet known who will take on the daunting roles of Captain Mainwaring and his platoon. The 2016 Dad's Army film featured Toby Jones as Mainwaring, Bill Nighy as Wilson, Tom Courtenay as Jones, Michael Gambon as Godfrey, Blake Harrison as Pike, Daniel Mays as Walker and Bill Paterson as Frazer.
The BBC's one-off 2015 comedy drama We're Doomed! The Dad's Army Story, about the genesis of the hit sitcom, featured the likes of John Sessions, Mark Heap, Kieran Hodgson, Julian Sands and Shane Richie as the actors.
Casting details will be revealed in coming weeks.
Pete Thornton, head of scripted commissions at UKTV, says: "The Lost Episodes are currently being cast, with an extensive hunt on to find the perfect candidates to take on the daunting task of bringing these much-loved comedy characters to life once more. We've been working on this project for several years and will be respecting the genius of the original series. If ever there was a time to 'stick to the script' then this is it. We are hugely excited and not a little intimidated by this opportunity but being plucky (and hopefully not too incompetent) Brits we aim to see the task through."
Gerald Casey, Gold's channel director, added: "As a Dad's Army devotee, I'm utterly thrilled that we're exclusively bringing these legendary lost masterpieces from Jimmy Perry and David Croft to life again after fifty years."
Wednesday 3rd October: Additional details clarified and quotes added.
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