Neil Patrick Harris has "no interest" in finding out if he is his twins' biological father.

The 'How I Met Your Mother' actor and his husband David Burtka welcomed twins Gideon and Harper into the world via a surrogate in October 2010 but they don't care which of them has genetic links to each of the kids.

He said: "We inserted one of my sperm and one of David's sperm into two eggs with the hope that they would both take, just because we both wanted to be dads biologically. And both took, miraculously.

"I have no interest in [finding out]. We are their parents and I love them both implicitly."

However, Harris admitted he has "suspicions" as to which of the twins is biologically his and which is Burtka's.

He said: "We certainly have suspicions just based on their behaviour."

The 41-year-old actor came out as gay in 2006 and admitted his parents were initially worried his sexuality "meant bad things".

He added to Barbara Walters: "[My father] comes from a military, more biblical background.

"They were worried that it meant bad things, that I was going to be in sex clubs risking my health and having a ton of partners. It didn't take long for me to prove to them that I'm not that way."

However, he admitted his father has since "done a 180" and accepts his sexuality and marriage.

He added: "He treats David just like he would any spouse."