The Phoenix (1981)

An archaeological expedition in Peru exploring ancient Incan ruins uncovers a strange casket. When the seals are released, a white man, somehow still alive is discovered. The man turns out to be Bennu, a visitor from another planet. Information he was supposed to have had been stored in the casket, but was destroyed by the archaeologists when they opened it. Bennu must learn to survive on earth, avoiding Peruvian government representatives who want to worship him as a god, and US government agents who want to disect an alien.