Matthew McConaughey had "no idea" his son was interested in acting

Matthew - whose mom Kay McConaughey, 93, also appears in The Lost Busy - told E! News: "He's introducing himself and I happen to be alongside him and in some of the same scenes of him which is pretty cool.

"Three generations. My mother has always been a performer and so she's been films. I had no idea he was even interested.

"He came back four times asking me, 'Can I read for it?"

Matthew pitched his son to the casting director and then Levi's audition was sent to director Paul Greengrass for consideration - but without revealing his connection to the movie's lead star.

He said: "They got him on camera, read for it and I said 'Wow, he can hold the frame, he's got the instinct for it.'

"They send it to the director and they say, 'If we do that, let's take the name off-my last name off-to send to the director. And Paul looks at it and says, 'That's the kid!'"

And Levi was stunned to be offered the role.

He said: "I knew it was a good audition and I was like, 'OK. This is good.' But I did not think I was going to get the part.

"I've never acted before, especially on this level, and so I got the call. I remember my dad gets the call and he handed me the phone and I'm like, 'Okay?' And it's the director Paul Greengrass and he goes, "Hey bud, how would you like to come over to Santa Fe, New Mexico, and play Shaun?' And I was like, 'What??'"

Levi tried to play it cool when he got the news but couldn't hold back his emotions once he got off the phone.

He said: "I was trying not to start crying on the phone so I was like, 'Yeah, that would be amazing. Thank you so much. This is great.'

"I hang up the phone and I started crying."

As well as Levi, Matthew and his wife Camila Alves are also parents to Vida, 15, and 12-year-old Livingston.