Frank Stallone reveals brother Sylvester 'tortured' him and once locked him to a fire escape with military handcuffs

Frank Stallone has revealed his brother Sylvester once locked him to a fire escape with military handcuffs.

The 70-year-old musician has opened up on his relationship with the 74-year-old Rocky star, and recalled how his older sibling "tortured" him when they were younger.

He exclusively told BANG Showbiz: "Oh god, he tortured me. I remember once we went to an Army Navy store that was down the street. In those days, Army Navy stores were great because it was all real World War II, Korean, and military gear.

"It was cheap! So, he got the bright idea - and I think stole some money from my parents, like two dollars - and bought these black military handcuffs.

"He goes, 'Come here, I wanna talk to you'. So I went out onto the fire escape, and he handcuffed me and left me there."

Frank laughed as he recalled the hilarious moment, and even remembers the moment their father Frank Sr. came home to see the scene.

He added: "So my father's walking up the steps to the fire escape thinking, 'What the hell's going on?' I'm sitting there, straddled with these black military handcuffs.

"Of course, he bought them cheap because they didn't have a key. So now they have the fire department to come and cut the handcuffs out. So there you go - that's how we roll!"

Frank - who has told his own story in a new documentary movie Stallone: Frank, That Is - also recalled a time when the two brothers decided to knock through the wall of their respective New York apartments and became "roommates".

He smiled: "That's when we were somewhat roommates. We lived next door - I think we paid maybe $80 (S$106) a month, maybe!

"And I was still standing on the street corner - busking, I guess what you would call busking. It was cold, man! When I tell you it was cold, it was freezing!

"I would stand out there, all this hair down past my shoulders, and sit there and sing songs. I think when you're 20 years old, you really have no sense of mortality at all.

"I mean, everyone's alive - even your grandparents are alive, sometimes your great-grandparents. So you really don't have any sense of, 'Well gee, I could catch pneumonia out there'. You don't really think about stuff like that."