The American actor claims his father always told him he would go out making love to his mother – and apparently that is exactly what happened when he died in 1992

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.