One word Matthew McConaughey's mum said to him that made him realise Woody Harrelson could be his brother

They're two of Hollywoods most recognisable names, faces, and voices - and while they've created a strong friendship over the years, life may be a little closer than a mere bromance for Matthew McConaughey and Woody Harrelson.

The two actors, who both hail from Texas in the US, have formed an endearing friendship over the years as they both became two of the biggest stars to grace the silver screen.

Starring opposite each other in the first season of True Detective back in 2014, Harrelson and McConaughey graced our TV sets in one of the best shows of the year that is still critically acclaimed to this day.

But away from work, McConaughey and Harrelson could possibly be related. And not loosely, we're talking brothers.

Despite them only meeting for the first time in 1999, where they both starred in comedy film EDtv, their connection seems to go back a lot further than either one of them realised.

The situation all comes down to a conversation between the two of them while they were on holiday in Greece with family.

That included McConaughey's mother, Mary Kathleen 'Kay' McConaughey.

Explaining what happened next, McConaughey said there was one word his mother said that made their connection seem a lot deeper than anyone could have thought.

Are they bros? (Lester Cohen/WireImage)

"In Greece a few years ago, we’re sitting around talking about how close we are and our families," the 54-year-old said on the Let’s Talk Off Camera with Kelly Ripa podcast.

"And my mom is there, and she says, 'Woody, I knew your dad'. Everyone was aware of the ellipses that my mom left after ‘knew’.

"It was a loaded K-N-E-W."

He also said: "And that’s part of our bromance, right? My kids call him Uncle Woody. His kids call me Uncle Matthew etc etc. And you see pictures of us and my family thinks a lot of pictures of him are me. His family thinks a lot of pictures of me are him."

The Interstellar actor said the two film stars went on to 'unpack what this 'knew' meant and did some math'.

They found out that Harrelson's dad had been on furlough at the same time that McConaughey's mum and dad were in their second divorce (they got married three times, no joke).

Woody's dad knew Matthew's mum (Jeff Kravitz/FilmMagic)

Harrelson said: "The year of [McConaughey's] birth, nine months before, she was on a sabbatical from her relationship with his supposed father, Jim."

"Then there’s possible receipts and places out in West Texas where there might have been a gathering, or a meeting, or a ‘knew’ moment," McConaughey added.

The duo have previously spoken about doing DNA tests to see if this was, in fact, reality, and McConaughey and Harrelson share a dad - with no other than Maury Povich even offering a helping hand.

But so far, they have edged away from this due to McConaughey being uneasy at the idea of finding out his father wasn't his biological dad; something he's believed his entire life.

However, he did respond to Povich's offer, saying: "I don't know if we're gonna do it on your show, but I like the way you're thinking."