Nine long-lost episodes of Doctor Who which have not been seen since the 1960s have been recovered after they were tracked down to a store room in Nigeria, gathering dust.
The discovery will cause much excitement for devotees of the long-running series, for which there are dozens of missing episodes dating back to its early years
The previously lost nine shows were among 11 traced to a television relay station and the find brings back to life an entire six-episode story, while another is almost complete.
The newly found programmes - which introduce the character of Alistair Lethbridge-Stewart, better known to audiences as The Brigadier - will be available on iTunes from today and will later come out on DVD.
Phillip Morris, the director of Television International Enterprises Archive, unearthed the programmes by looking up the records of overseas shipments of tapes made by the BBC.
The stories, The Enemy Of The World (1967) and The Web Of Fear (1968) and both starring Patrick Troughton as the second Doctor, have now been remastered by BBC Worldwide, the corporation's commercial arm.
Mr Morris said: " I remember wiping the dust off the masking tape on the canisters and my heart missed a beat as I saw the words Doctor Who. When I read the story code, I realised I'd found something pretty special."
Only one episode of The Enemy Of The World - which featured Deborah Watling as companion Victoria and Frazer Hines, later to find fame in Emmerdale as Jamie - had remained in the archives, so the addition of programmes one, two, four, five and six have completed the story.
Fiona Eastwood, director of consumer products, BBC Worldwide, said: "We are thrilled with the recent discovery of The Web Of Fear and The Enemy Of The World and we're very happy to be launching re-mastered versions of these treasured episodes to fans as we celebrate the 50th year of Doctor Who."
The BBC still had the first edition in the Web Of Fear story, and the new finds mean only number three is missing. The tale introduced Nicholas Courtney as Lethbridge-Stewart, who began with the rank of Colonel but later became Brigadier.
The missing episode has been recreated using 37 still images which were available and the original audio which survived.
Many programmes from the era, along with many classic shows, disappeared as a result of efforts to save space. There are still 27 Doctor Who stories which have not been recovered or for which episodes are missing.
The show celebrates its half-century on November 23.