Sad news.

The German bodybuilding star appeared in shows including Netflix's Dogs of Berlin.

He is said to have collapsed and died while running on a treadmill at the gym.

Actor and filmmaker Said Ibrahim paid tribute to Pirbazari, whom he met two years ago while working on a film together.

Ibrahim said he didn't know 'how to start this video', and went on to talk about how despite Pirbazari's muscles and dangerous look, he had a 'soft heart'.

He continued: "Vito had a soft heart like a ten-year-old, I swear to you."

"I got the sad news that he passed away yesterday and that really knocked me down and threw me completely off track […] I wish the family a lot of strength. I wish his friends a lot of strength."

Ibrahim added that he was 'simply stunned' to hear the news of his friends death.

It seems as though he suggests in the social media video that Pirbazari had a heart attack whilst running on the treadmill, however this has not yet been confirmed.

Just days before his death, the 44-year-old uploaded a photo of himself to Instagram, sharing that he had returned to the gym after 12 weeks off.

The break from fitness was due to him survived a near-fatal car accident in which he suffered a fractured vertebra, tissue damage, and both of his legs required stitches.

The star shot to fame as part of YouTube fitness influencer group, Hardgainer Crew.

His own YouTube channel boasted over 200,000 subscribers, however he had quit his channel a few years ago after becoming a father.