The BBC said Thursday it has remastered the tapes, and is making two multiple-episode stories -- "The Enemy of the World" and "The Web of Fear" -- available exclusively on iTunes.
Eleven "Doctor Who" episodes were discovered -- nine of which have not been seen for 46 years -- by Philip Morris, director of Television International Enterprises Archive, by tracking records of tape shipments made by the BBC to Africa for transmission.
"The tapes had been left gathering dust in a storeroom at a television relay station in Nigeria," Morris said in a statement. "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 realized I'd found something pretty special."
"For many, this will be their first chance to watch these long-lost 'Doctor Who' stories," said Beth Clearfield, the BBC's senior vice president of digital distribution and business development. "We're thrilled to partner with iTunes in bringing these missing gems back to new and longtime fans after all these years."
On Nov. 23, "Doctor Who" will celebrate the 50th anniversary of the premiere of its first episode, "An Unearthly Child," on BBC television.
The BBC said a number of episodes from the first series of "Doctor Who" were lost as a result of BBC archive space-saving measures.