By Alice Udale-Smith, News Reporter
Mark Ruffalo has apologised after accidentally streaming the first few minutes of his latest film Thor: Raganok on Instagram.
The mishap happened after the Hulk actor used his mobile phone to live-stream from the red carpet of the Los Angeles world premiere.
Ruffalo continued filming as the cast appeared onstage ahead of the film's showing, but forgot to turn off the live-stream when the movie started.
Instead he placed the phone in his pocket, meaning those watching were able to listen to the audio of the first few minutes of the film.
The actor did not seem to be too upset about the mistake.
"I felt bad you weren't there with me. I snuck you in. In my pocket," he tweeted to his followers on Thursday.
"All kidding aside… I'm sorry Marvel," he later posted. "Can I have my phone back?"
— Mark Ruffalo (@MarkRuffalo) October 12, 2017
About 2,500 people were watching the stream during the opening minutes of the film.
Many commented questioning how long it would take before the actor realised his mistake, while others posted on Twitter telling Marvel to get the actor to turn the recording off.
After a few minutes the stream ended but it is not clear whether Ruffalo realised what was happening or it stopped automatically.
The Hollywood Reporter said audience members had to hand their mobile phones in to security before the film started.
Marvel has worked hard in the past to prevent details of upcoming projects from leaking.