Premiering in 1963, Doctor Who is one of the most popular sci-fi shows in the world. The show tells the adventures of an alien called the Doctor who travels across time and space on his TARDIS.
It was eventually sold to other countries for broadcast and one of the regions that the series was broadcast in was Latin America, complete with it's very own Spanish dub made in Mexico. In order to do so, the BBC sent prints of the episodes to be dubbed with an M/E track, including the sound effects and music. Twelve of the first seventeen First Doctor episodes were broadcast in Venezuela, Mexico, Chile and Costa Rica with "Marco Polo" and "The Reign of Terror" to be sold to Venezuela (the first country to broadcast Doctor Who) in 1967 but the purchase of the episodes were cancelled and "The Romans" and "The Crusade" were skipped. Instead, "The Chase" was the last episode of the series to air in Latin America until 1980, when the series got back with the Fourth Doctor.
The episodes "Robot" through "The Invasion of Time" were transmitted in the aforementioned countries, as well as Nicaragua, Colombia, Ecuador and Puerto Rico, with the Time-Life Television edits. Interestingly, although they broadcasted the same Time-Life versions, Mexico and Chile had different titles for some episodes (For example: In Mexico, the title of "Robot" was left but in Chile it was called "Muerte de un robot", or "Death of a Robot").
The fate of the dub is unknown, but prior to 1978 the BBC had held onto dubbed prints of "The Dalek Invasion of Earth" Part 6, all of "The Web Planet" and "The Space Museum" Part 4, which were probably sold to Costa Rica in 1971, but after 1978 the archives only contained "The Web Planet" Part 6 and "An Unearthly Child" Part 1, while "Inside the Spaceship" Part 1 and "Planet of Giants" Part 3 are known to exist in the hands of private collectors.
Eventually, "The Web Planet" Part 6 was included in the DVD release of the arc, but only a single clip that aired on BBC Mundo in 2013, courtesy of a diehard fan from Mexico, has surfaced on the internet. The American DVD is a tough find while the European DVD is an easier find, but the entire episode has yet to be ripped from either DVD.