Lane Cove Theatre Company's production of Holding the Man has had a sold out season, but it appears not everyone is a fan of the show.
After last night's performance, 12 cast and audience members returned to their vehicles outside The Performance Space at Longeuville, to find their tyres had been slashed.
A police spokesperson said they would investigate "motives of bias" behind the attack.
It is not the first time the production, which tells the 15-year love story of two men, has been targeted.
Earlier this month, posters advertising the play at Lane Cove Plaza were ripped down.
The attack comes at a time of significant debate about LGBTI rights is Australia, and less than three days after the Australian Electoral Commission closed enrolments ahead of a national survey on same-sex marriage.
'Somebody was targeting us'
Trent Gardiner, one of the actors who had his tyres slashed, said the attack had left people angry.
"It certainly leads you to believe that somebody was targeting us," he said.
"We were appalled and shocked. I don't expect that to happen here."
North Sydney MP Trent Zimmerman attended the production's opening night but said it had since been "overshadowed by a series of hateful attacks".
"This type of behaviour has no place in our local community and should be condemned. Just disgraceful that any person would be targeted in this way," he posted on Facebook.
Mr Gardiner said only vehicles outside the venue on Sydney's north shore had been targeted while others parked on the street remained untouched.
Police said they were called to the theatre on Christina Street just after 10:30pm after reports vehicles had been damaged.
"Police have been told the vehicles were owned by members of a theatre group," a spokesperson said.
"Police will investigate all motives including motives of bias."
The show's final performance is tonight.