Lure of the Islands (1942)

Tana, a captivating half-caste girl from the South Seas, finds herself smitten with FBI agent Wally and dreams of marrying him to escape her island life. Wally, accompanied by his friend Jinx, is on the island to look into suspicions of Japanese espionage. He proposes marriage to Tana under the condition that she assists him with his investigation. As they uncover a hidden radio set that receives Japanese transmissions, Wally realizes that the local Commandant is collaborating with the enemy and plotting an invasion of their island.