The opening night of Melbourne’s International Comedy Festival was abruptly cancelled on Wednesday after the shock death of a patron midway through a show.

The man died from a suspected heart attack just over an hour into the Opening Night Allstars Supershow at the Palais Theatre.

“Melbourne International Comedy Festival regrets to confirm that there was a medical emergency,” a festival spokesman posted to Instagram.

“The show was stopped and cancelled. The festival will be in touch with all ticket holders tomorrow.”

Victoria Police said the man could not be revived and died at the scene.

Veteran comedian Dave Hughes paid tribute as news spread through the festival grapevine.

“All performers’ thoughts are with the family affected,” Hughes wrote.

Another performer, Tahir Bilgiç, said: “Sad news but correctly handled all around … well done everyone and thoughts with those involved.”

One patron told the Daily Mail the incident happened during a performance by headline act Michael Hing, and the comedian was unaware for some time.

People in the audience attempted CPR as Hing continued his set on stage.

“It would have been at least 15 mins worth before the show stopping, and it only stopped as patrons yelled to stop performing,” the audience member told the Daily Mail.

Another audience member said people started to leave, and were comforting each other. 

“It was only when a few people, who were leaving, got up and were loudly talking or arguing with a staff member before leaning over and shouting at the comedian on stage to stop the show that anything happened,” they said.

“The public and paramedics were there for a good 15-20 minutes in the dark doing CPR before the show stopped.

“I can’t believe they (the organisers) didn’t communicate with backstage to halt the show, and that it took the public to yell out to the comedian to stop for something to happen.”

Attendee Andrea Bortoli told The Age she was sitting in the upper level’s front row when she noticed movement behind her.

“There was obviously something going on at the back, and we were kind of trying to figure out what was going on,” she said.

“Then people started leaving. And then it became quite obvious that someone was getting CPR.”

Bortoli said people around her were crying as they left the theatre.

“It was just obviously really distressing, so we wanted to leave,” she said.

The Melbourne International Comedy Festival, one of the three largest comedy festivals in the world, runs until April 20.

It includes a mix of stand-up comedy, cabaret, theatre and street performances.