Leonardo DiCaprio and his The Revenant co-stars were often mistaken for homeless men by other vagrants while shooting the survival epic in a remote part of Canada.

The actor portrays real-life 19th century frontiersman Hugh Glass, who is mauled by a bear and left for dead, in the new movie, and he had to grow a thick, bushy beard for the part.

The facial hair made him and his castmates, including Tom Hardy and Domhnall Gleeson, unrecognisable in the Rockies, and they were frequently offered a beer by local tramps whenever they headed into town.

"When we came into town, there was a lot of like, homeless people that would recognize us as their friends and offer us beer and things like that and we'd have conversations with them," Leonardo recalled to talk show host Ellen DeGeneres, "but a lot of the times, we were very unrecognisable to most of the people we knew!"

Despite having the beard, the 41-year-old reveals he still had to spend five hours in the make-up chair every day to make his bear attack look appear real onscreen - even though director Alejandro Gonzalez Inarritu faced a daily race against time to make the most of the limited natural light as they worked on location in the freezing conditions.

"That was actually wax," he explained of the 'ice' in his beard. "I had a fantastic make-up artist in this movie who did all the stuff from the bear mauling and all this wax that she dribbled all over my face every day. It was about a four to five hour make-up job every day with all the scars... so again, it was just a joy, the whole experience!"

However, Leonardo confesses he was glad when he was finally able to shave off his beard.

"I don't think I'll ever have a beard like that ever again, unless it's for a role, but it's hard to maintain," he said. "Stuff gets in there; you're eating and then food falls in there... You have to shampoo it, I did (condition it), 'cause you do want it to be soft, otherwise it gets like a Brillo (scouring) pad!"