ZAC Efron and Alexandra Daddario scotched rumours that they are an item ahead of the Australian premiere of Baywatch in Sydney.
"As far as I know, she hasn't said yes," said Efron, who plays a disgraced Olympic gold medal-winning swimmer in the tongue-in-cheek reboot of the popular '90s television series.
Daddario, who plays a gutsy new recruit to the close-knit team of lifeguards, said feverish on-line speculation of a budding off-screen romance "makes sense because we are love interests in the movie".
"But this is a lot for me to handle," she laughed, gesturing towards Efron.
The former High School Musical star went to extraordinary lengths to sculpt his already buff body for the role.
"It's all for the character, to achieve an aesthetic and a look. It's amazing how much you can put yourself through to achieve that transformation into the character," he said.
Daddario, who is reunited with San Andreas co-star Dwayne Johnson in the Baywatch movie, formerly dated Logan Lerman, with whom she appeared in the Percy Jackson films.
When he's in Los Angeles, Efron shares a house with his younger brother, Dylan, 25.
"He does Ironmans, which are like triple triathlons, consistently so he probably looks more like an Olympic swimmer than I do,'' says the actor.
"I am lucky, I get along great with my little brother, who is technically the bigger brother now. We both love the same things when we are home."
At last night's star-studded premiere in Sydney, Efron told guests to 'strap in' for a wild ride, while Daddario said their aim was to make a "funny and raunchy" movie.
He said he would always make the effort to come to Australia to promote his films because "you guys have supported me since day one".
He was also full of praise for his co-star Dwayne Johnson, who was not in attendance and recorded a message for the audience. Efron got some 'awhs' from fans when he said "the biggest muscle that dude has is his heart".
Baywatch opens in Australia on June 1.