Speculation about the status of their relationship arose as the 28-year-old actor suddenly removed all traces of the model/designer on his social media accounts.
He even unfollowed her on Twitter and Instagram, reported Ace Showbiz.
The duo were last seen together at the MTV Movie Awards. Sami herself has not deleted their pictures which were taken at the event held Sunday, April 10.
There was no sign that there's trouble in their relationship as they looked happy in the photos.
Efron's move to unfollow Sami comes amid rumors that she cheated on him while attending Coachella last weekend.
Efron has been busy filming "Baywatch" movie in Miami, Florida. He stars opposite Dwayne "The Rock" Johnson, Kelly Rohrbach, Alexandra Daddario and Priyanka Chopra in the film.