British wrestling champion Adrian McCallum - known by his ring name Lionheart - has died.
The 36-year-old from Ayr was the reigning ICW (Insane Championship Wrestling) world heavyweight champion and also competed in WWE and TNA.
In a statement ICW said they were heartbroken by the news. No further details about how Mr McCallum died have been released.
His death has prompted tributes from across the wrestling community.
We are heartbroken to learn of the tragic death of ICW World Heavyweight Champion, Adrian ‘Lionheart’ McCallum. Adrian was a mainstay of ICW and British professional wrestling. Most importantly, he was our friend. His passing leaves a huge hole in the lives of those who knew him. pic.twitter.com/qmjnZTb5Lb— ICW (@InsaneChampWres) June 19, 2019
Writing on Twitter, ICW said: "We are heartbroken to learn of the tragic death of ICW World Heavyweight Champion, Adrian 'Lionheart' McCallum.
"Adrian was a mainstay of ICW and British professional wrestling. Most importantly, he was our friend. His passing leaves a huge hole in the lives of those who knew him."
WWE wrestler Cedric Alexander said he was "crushed" to hear of McCallum's death, while fellow WWE star Paige - real name Saraya-Jade Bevis - said she would be "forever grateful" to have known him.
Pete Dunne, the longest-reigning WWE UK champion, tweeted: "I always looked up to Lionheart's professional approach to wrestling when it was far from that at the time. People like him were pivotal in the growth of a scene that has lead to so many people being able to do this for a living."
British wrestler Will Ospreay, who currently competes in Japan, said: "Every time I've met you, you have been nothing but a sweetheart. I honestly cannot believe I'm writing this tweet.
"Devastated doesn't cover how I feel."
Tribute was also paid by Scottish actor Greg Hemphill, known for appearing in the sitcom Still Game.
"Heartbroken for the whole wrestling family tonight," he said. "What a talent and what a lovely guy. He will be sorely missed."
Lionheart was one of the mentors in BBC Scotland series Rogue to Wrestler, where eight recruits competed against each other to become professional wrestlers.