The Phantom from 10,000 Leagues

Oceanographer Ted Stevens (Kent Taylor) meets Bill Grant (Rodney Bell), government investigator, at the scene of another beach murder caused by a hideous sea monster that stands guard over a glowing underwater Uranium mine.
Meanwhile marine biologist Professor King, who created the monster in his laboratory, is being pursued by a beautiful femme fatale who is blackmailing or killing everyone in sight in an effort to acquire King's top secret files for the Russians. (official distributor synopsis)