The crime drama - based on Henning Mankell's novels - recently wrapped its third series on BBC One, with the new episodes now airing in the US on PBS Masterpiece.
"If we went into a fourth series, which we hope to with three more films, they would probably include The White Lioness - a book that has not been adapted before in any of the Wallander series, which is set in South Africa," Branagh told Assignment X.
The actor went on to confirm that the final two Wallander episodes would be based on Mankell's final book featuring the character, The Troubled Man.
"We would make two films of that very dense book," he explained.
However, Branagh also admitted that he is open to making a fifth series of Wallander if Swedish novelist Mankell were to write more books in the future.
"Henning Mankell had said recently that he enjoyed the series so much that it made him want to write some more [books]," the star explained. "I feel our series has particularly taken its DNA from these novels. So if there are more of those, I'm sure we might think about it."
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Watch a trailer for Wallander below: