The radio shock jock, 49, and Efron, 33, are close friends, with Sandilands saying in an April 21 broadcast of his radio show that he found out about the split in a recent phone call with the actor.
Now, a possible reason for the breakup has emerged.
According to an Us Weekly source, the split was a long time coming.
“Zac is about to start a busy year of filming and wanted to make a clean break now,” the insider said. “Zac is secretly relieved about this turn of events as he feels she would be a distraction to him during the filming of the intense drama.”
Another source told People that the split occurred because “it just didn’t feel right to him anymore”.
Efron and Valladares, 25, met when the Australian model was working as a waitress at the Byron Bay General Store cafe in June 2020.