The Jurassic Park actor stars alongside newcomer Julian Dennison in the adventure comedy as a grumpy old foster parent whose charge Ricky runs off into the New Zealand bush. He tracks him down but when an injury forces them to stay in the forest for weeks, social services fear Ricky has been abducted and a national manhunt ensues.

For the majority of the film, Sam is filming just with Julian, who was 12 years old at the time, and two dogs, named Zag and Tupac, in the forest and he admits getting the pooches to do as they were told was a challenge.

"The dogs were much more stressful than Julian... they don't understand English very well," he told WENN when asked if working with both kids and animals was stressful. His young co-star added, "You were like 'Tupac, come here!' and they'd just look at you or just walk off."

"You fed those dogs treats all day," Sam told Julian. "I didn't think those dogs deserved those treats."

Julian, now 13, loved working with the canines but admits one downside was discovering old dog snacks in his pockets when he put his costume on weeks later, as they had disintegrated so much that had "become one" with his clothes.

The film is directed by Taika Waititi, who is currently making his first Hollywood blockbuster Thor: Ragnarok. Taika appears as a preacher in the movie, which also co-stars Flight of the Conchords actor Rhys Darby, who was "impossible" to keep a straight face around, according to Sam.

"One of the problems with this film is it's not really a comedy although it's pretty funny," Sam explained. "But we have every funny actor in New Zealand just about, apart from me, I'm not funny at all. My job was not to be funny."

"Your job was to be funny... You had one job!" he laughed to Julian, who joked back: "And I failed!"

Hunt for the Wilderpeople premiered at the Sundance Film Festival in January (16) and is released in the U.K. on Friday (16Sep16).