Woody Harrelson wants to have a DNA test to see if Matthew McConaughey is his biological brother, but admits it is "much more of a big deal" for his fellow actor.

Woody Harrelson wants DNA test to see if Matthew McConaughey is his biological brother

Woody Harrelson wants DNA test to see if Matthew McConaughey is his biological brother

The pair have been close friends for years, but Matthew recently told how they started questioning whether they could be blood relatives after the 'Mud' star's mum revealed she previously knew Woody's dad.

Woody, 61, is now keen to get a test to find out the truth, but he admits Matthew feels he would be "losing a father" if the results were confirmed.

Speaking on 'The Late Show with Stephen Colbert', he said: "We want to go for a [DNA] test, but for him, it’s a much more big deal.

"I mean he feels like he is losing a father. But I’m like, no, you’re gaining a different father and a brother."

Woody admitted he and Matthew started to wonder whether they were related when the 'Dallas Buyers Club' star's mother told them she used to know Woody's dad.

He said: "We talked to Ma’ Mac, Matthew’s legitimate mother, and she let us know one time ... I mean, this is crazy.

"We were in Greece watching the US team win the World Cup and I don’t know, I mentioned something about regrets.

"And I said, ‘You know, it’s odd that my father has no regrets.’ And I have known Ma’ Mac a long time, and she goes, ‘I knew ... your father.’ And it was the ellipses I found a little troubling, or interesting. ‘I knew your father.'

"The year of [Matthew’s] birth, nine months before, she was on a sabbatical from her relationship with his supposed father, Jim."

Last week, Matthew opened up about the same conversation he and Woody had with his mother.

Speaking on Kelly Ripa’s 'Let’s Talk Off Camera' podcast, the 53-year-old star explained: "You know, where I start and where he ends, and where he starts and I end, has always been like a murky line. And that’s part of our bromance, right? My kids call him Uncle Woody. His kids call me Uncle Matthew. 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 ...

"In Greece a few years ago, we’re sitting around talking about how close we are and our families. 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.

"We went on to unpack what this ‘knew’ meant and did some math and found out that [Harrelson’s] dad was on furlough at the same time that my mom and dad were in their second divorce. 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."

However, Matthew admitted he is not keen to get a DNA test.

The pair are to co-star in comedy series 'Brother From Another Mother' for Apple TV+, in which they will play fictionalised versions of themselves.

Woody and his family will live with Matthew at his Texas ranch.