Mystery Island

Directed by Gordon Flemyng

Written by Terry Nation

Cast: Steve Forrest as John Mannering, Sue Lloyd as Cordelia Winfield

Released 1966

Attempting to locate a missing shipment at the docks in Macau, Cordelia stumbles upon a murder on board a cargo vessel. She is immediately taken prisoner, and John Mannering stows away in order to free her, unaware that he is about to uncover a plot to sabotage a US space mission.
According to jensencv8.webbly.com, this was "a re-edit of the episodes Storm Warning and The Island",  #15 & #16.