If you read the Biography for Jeffrey Hunter you will notice a mistake. 1.) How did he film an episode of Star Trek in 1989 when he died in 1968? I believe the digits were transposed by the writer and nobody caught this. http://www.imdb.com/name/nm0001374/
Terresa: It is possible to submit corrections to various types of information on IMDb by clicking "Edit page" from most pages on the site. But in this case, there doesn't appear to be a mistake.
IMDb doesn't say that Hunter filmed an episode of "Star Trek" in 1989. Rather, his acting credit for the "Star Trek" episode "The Cage" is the series pilot, which was filmed in 1964 and completed in 1965 but not shown at that time.
Almost all of the footage from "The Cage" was incorporated into the "Star Trek" episodes "The Menagerie, Parts I and II", which were broadcast in 1966. Hunter has Archive Footage credits for those episodes (because he didn't film any new footage for them -- they just used scenes from the previously existing pilot).
"The Cage" was not distributed to the public in its original format until 1986, when it was released on home video. (And it was first broadcast on television in 1988.)
Even though Jeffrey Hunter died in 1969, the listing of "The Cage" in his filmography under 1986 is correct under IMDb policy.
(By the way, I assume you are referring to Hunter's filmography on IMDb, not his biography. The biography at http://www.imdb.com/name/nm0001374/bio doesn't say anything about the 1986 release of "The Cage", and his biographical trivia clearly indicates that he filmed the episode in 1964 even though it wasn't broadcast until 1988.)