Sylvester Stallone, 68, 'forced to break up fight with real-life boxer Tony Bellew' on the set of new Rocky spin-off movie Creed

Fight! Sylvester Stallone, 68, - pictured on set in Pennsylvania last month - has had a real-life punch up on the set of new Rocky spin-off movie Creed, according to TMZ

In a case of life imitating art, actor Sylvester Stallone has been involved in a brawl on the set of his new Rocky spin-off movie, Creed.

According to TMZ, the 68-year-old action star 'went ballistic' as tried to break up a fight while filming the latest installment of the franchise in Aston, Pennsylvania on Monday.

The site claims that British boxer Tony Bellew, who stars in the movie, got into an altercation with another actor on set, that was not part of the script.

A representative for the studio told TMZ that the incident never became physical, despite several eyewitnesses saying otherwise. 

DailyMail.Com has reached out to representatives for Stallone who have so far been unavailable for comment.

It is not known what caused the incident at this stage, but Stallone and a few others are said to have managed to break up the fight.

Police were called to the scene but it is unclear if any charges will be made.

Pictured: British boxer Tony Bellew - pictured in November last year - reportedly got into a fight on set of the new Rocky spin-off movie, according to TMZ

Action hero: Sylvester at the Cannes Film Festival last year, with Antonio Banderas, Ronda Rousey and Mel Gibson  

Bellew posted a picture of himself posing at the Rocky statue and a video of him running up the famous steps in Philadelphia.

Speaking after his victory over Nathan Cleverly last year, a coy Bellew said: 'I’m going to Hollywood in December for an assignment. I’ve been sought-after for a long time. I hope it’s a speaking part because no-one wants to look at this face if I’m not talking. My life’s going to change.

'I’ve had the contracts sitting in front of me for weeks because I wasn’t signing them. If this fight had gone wrong I wasn’t signing, I was going home to be depressed.'

'I can’t go into the details but let’s just say it’s big. It will be 40-odd days of filming, I just hope I can do it.'

Classic: Sly in the original 1976 classic movie Rocky, which has spawned six other movies in the franchise 

Back in the ring: Sylvester pictured on the set of Creed last month in Pennsylvania 

The Rocky spin-off will showcase the boxing career of Apollo Creed’s grandson Adonis