Ilya Salkind, 63, flew to his native Mexico City recently to oversee work on a property he inherited from his late mother.
Reports suggest he left the house on Sunday (30Jan11) to "handle some errands and get some dental work done" - but he never returned and friends filed a missing persons report with Mexican police on Tuesday (01Feb11).
Investigators tracked Salkind down to a local hospital on Thursday morning (03Feb11), according to TMZ.com.
It is unclear why he was unable to contact anyone to alert them to his whereabouts, although he is said to have been sedated by medics.
Salkind is known for securing the rights for a live-action Superman film in 1974, leading to the 1978 movie starring Christopher Reeve as the Man of Steel, directed by Richard Donner. He went on to executive produce two Superman sequels in 1980 and 1983.