Entitled Triplets, the new film would see Schwarzenegger and DeVito reunited, with Murphy as a (presumably long-lost) third brother.
The original Twins was a well-received comedy directed by Ivan Reitman, in which Schwarzenegger and DeVito play the results of a genetics experiment that produces radically dissimilar twin brothers who grow up in entirely different enviroments. It was made at the height of Schwarzenegger's action-movie stardom, and showcased a hitherto little-suspected comedic side to his persona. It was a sizeable hit, taking $111m in the US and a further $104m worldwide.
There is no word yet as to who might direct the project, but Reitman is unlikely to take the helm again, according to the Hollywood Reporter, preferring at this stage to stay in the background as a producer.