Mara Maru is a 1952 American noir action film starring Errol Flynn, Ruth Roman and Raymond Burr.

Flynn did go on to appear in a British film The Master of Ballantrae that was released by Warners, and return to make Too Much, Too Soon where he played his friend John Barrymore.

[6] Gregory Mason (Errol Flynn) and Andy Callahan (Richard Webb) are partners in a post-World War II salvage business in Manila.

Still carrying a torch, she tells Mason and begs him again to give up the expedition and return with her to a normal life in the United States; once again he opts for money, pursued at any cost.

It turns out to be a diamond encrusted crucifix from a Catholic cathedral in Manila that has played a significant role in the movie, both spiritual and as part of the mystery of the trail of murders leading towards the treasure.

Exhausted from his flight, he is caught near the church steps by Senor Ortega, the brother of the man aboard the PT boat who had originally taken the cross for safekeeping from the invading Japanese.

Warner Bros announced in January 1950 that they had bought the film's story from Philip Yordan, Sidney Harmon and Hollister Noble.

[11] In September, Warners said that Errol Flynn would star and Gordon Douglas would direct[12] Richard Nash had written the script.

"[19] According to The New York Times The gobbledegookish title of Warner's Mara Maru is not the only obscure and unexciting thing about this stale adventure film.

Its wholly improbable build-up of a criss-cross of rivalries ... is bleakly confused and grossly tiresome, and when the action does finally get around to the business of diving for the treasure it is hackneyed and cheaply emotionalized.

[20]The Los Angeles Times said that "while its scenes of physical action are scarcely original ... they keep one's eyes on the screen with a fair amount of absorption.

"[22] Filmink later wrote that the film was a "soggy melodrama" which was "a throwback to the sort of thing Humphrey Bogart used to make – a tale of double-crossing and dirty dealings in an exotic port" with "too much talk, flabby handling, and a star off form.