Leonardo Dicaprio was driven ''mad'' by the fake moustache he had to wear on the set of 'Once Upon a Time In Hollywood'.

The 44-year-old actor plays struggling Western TV legend Rick Dalton in Quentin Tarantino's latest film, which explores the golden age of cinema at the end of the 1960s, and DiCaprio was required to transform his face with stick-on long facial hair for numerous scenes.

DiCaprio's long-time make-up artist Sian Grigg - who has worked with him since he starred in the 1998 film 'Titanic' - revealed the actor was less than pleased with his unruly moustache because it kept going in his mouth and he was constantly ''spitting out'' the fake hairs.

She said: ''The moustache drove Leo mad, because I had to leave it really long and it always went in his mouth.

''It was so hot out and the moustache kept going in his mouth, and he'd be spitting it out. He did the same thing in the scene as they filmed 'off camera' when he was supposed to be losing it a bit. It made us laugh as he kept spitting it out and the wig was quite long as well.''

The beauty guru copied the ''style'' of Spaghetti Western films to create the actor's exaggerated look, and she admitted Tarantino wanted him to look as ''unrecognisable'' as possible.

Sian told The Hollywood Reporter: ''It was meant to look phoney because they didn't have good materials back then like we do now. It was correct for the period - a Western film being made in the '70s.

''We were copying the style of films shot in that period and also covering Leo's character up to look different and unrecognisable, which in the movie he's not used to.''

DiCaprio also made sure to not get his haircut in the lead up to being on set, according to the film's hair department lead, Janine Thompson, and head of make-up, Heba Thorisdottir.

Janine said: ''When people start hearing that Quentin Tarantino is doing a '60s/'70s movie, word is out and people start growing out their hair, especially since his two previous films were Westerns.''

Heba added: ''Actors tend to grow out their hair in between jobs as well, which is beneficial, because they come into the trailer as a blank canvas for us.''