Matthew McConaughey's heartfelt reaction to finding out of his friend's death on the red carpet

This is heartbreaking.

Matthew McConaughey's heartfelt reaction to the death of esteemed playwright and actor Sam Shepard has been caught on camera.

The pair worked together on acclaimed 2012 film Mud and it's clear McConaughey holds a lot of respect for his co-star, who died aged 73 after experiencing complications from motor neurone disease, also known as ALS.

"What? Sam Shepard moved on?" McConaughey asks , before adding "Gosh darn it."

He takes a moment to gather himself and puts a hand to his head, shocked by the news, before responding further.

"Look, I'm not going to trivialise that situation, I just heard about it for the first time. But I always told [director] Jeff Nichols this, 'In Mud, the whole trailer for Mud could be Sam Shepard sitting in that green chair telling the boy about who Mud is'. It would be about a two-and-a-half minute trailer, but it would have been really badass.

"We lost one of the great ones. Great writer, great mind. Alright, see you in the next one, Sam."

The reaction was captured by Associated Press on the red carpet for his new film Dark Tower.

Newshub.