The Mad Doctor of Market Street (1942)

The mad doctor Benson pays a destitute man $1,000 to be the first
human subject of his regeneration experiments. When the man dies,
Dr. Benson boards a liner headed to New Zealand to escape police
search. The ship catches fire and sinks. In a life boat Benson
and five survivors land on a tropical island. He brings the
apparently dead wife of the native chief back to life and is
pronounced a god by the natives. Benson has the lifeboat burned
and tells his fellow survivors he intends to use them as subjects
of his further experiments.