Johnny Depp created Captain Jack Sparrow by turning up sauna to '1000 degrees' until it affected him mentally

Johnny Depp has revealed the secret technique he used to figure out the character of Captain Jack Sparrow.

While the main story of the original Pirates of the Caribbean was more about Will Turner (Orlando Bloom) trying to rescue Elizabeth Swann (Keira Knightley) from a motley crew of undead pirates, Jack Sparrow was by far the fan favourite character.

One of the funniest, most engaging things about his character was the way he seemed to be not all there, adding an element of madness and delirium to the swashbuckling seafarer.

However, Johnny Depp has also revealed that he worked out a really specific way of getting into character involving a really hot sauna.

He said: "I was just looking at various aspects of the character and I figured this is a guy who's been on the high seas the majority of his life.

"I figured he'd probably dealt with a lot of inescapable heat to the brain, so I cranked a sauna up to about 1,000 degrees and I sat in there for as long as I could until it started to affect me mentally.

"Which is to say I was very, very hot, as was my brain. What happens while I was in there, in that kind of heat you cannot stand still but if you move it kills you, so that in itself sort of gave me this, yeah, his brain has been boiled to some degree."

Depp went on to explain that he thought a good detail for Captain Jack would be if he was steady as a rock while on board a ship, but wobbly-legged and clumsy whenever he was on dry land, the opposite of sea legs essentially.

The actor told the company they could fire him if they didn't like where things were going, and since he did a whole bunch of Pirates of the Caribbean movies it's pretty obvious that Depp eventually won out.