Matthew McConaughey has opened up about the death of his father – revealing he died of a heart attack while in the throws of passion.

Oscar winning actor Matthew, 50, is preparing to unleash his memoirs after penning his upcoming book, Greenlights, which promises to give a detailed account of his life so far.

The book is believed to see the star open up about an incident where he was arrested while naked while also chronicling the ups and downs of his Hollywood career.

However, he also gives details about the heartbreaking moment he discovered his father, James Donald McConaughey, died.

An exert shared in People magazine explains: “I got a call from my Mom. ‘Your dad died.’ My knees buckled. I couldn’t believe it.

Matthew McConaughey has shared surprising details of his father's death (
Image:
WireImage)

“He was my dad. Nobody or nothing could kill him. Except mom.

“He’d always told me and my brothers, ‘Boys, when I go, I’m gonna be makin’ love to your mother.’ And that’s what happened. He had a heart attack when he climaxed.”

Matthew’s father, James, passed away aged 63 in 1992 when the star was in his early 20s.

Matthew is revealing all about his life through his new autobiography, Greenlights (
Image:
AFP)

Giving more information about his parents and their relationship, Matthew explained that things could be turbulent.

His oil pipe supply business owning father had married his school teacher mother, Mary Kathleen, there times – with the couple divorcing twice.

Matthew himself was born shortly after the couple married for the third time.

The actor told People: “They were, at times, violent.

“As I say in the book, that is how they communicated. They were divorced twice, married three times, I mean, yeah, it was like the Pacific Ocean in a storm.”

Matthew McConaughey’s book, Greenlights, is due for release on Tuesday 20 October 2020.