The Predator star first announced that a sequel – titled Triplets – was in the works at ComicCon in 2012.
In the original movie, Schwarzenegger played Julius Benedict, who was conceived by test tube and went on a search for his long lost brother.
And DeVito, 73, took on the role of his brother Vincent, who turned out to be much shorter and a crook after failing to get any of the good genes.
Speaking to ShortList in 2015, Murphy expressed caution at joining the project.
‘A couple of years ago I met with Arnold and Danny and some writer.
We had a meeting but I didn’t hear anything. I tell you – I’m not doing anything unless the script’s incredible.’
The first film’s director, Ivan Reitman, is set to return to the director’s chair.
