Daniel Radcliffe and Erin Darke are expecting their first child

Daniel Radcliffe is expecting his first child with Erin Darke.

The 33-year-old actor is set to become a dad for the first time, with a rep for Erin confirming that she's pregnant.

A source told The Sun: "Daniel is so excited to be a dad. His relationship with Erin is really special and everyone thinks they will be amazing parents.

"They have kept it pretty quite up until now but she can't hide her bump anymore."

Daniel and Erin are "absolutely thrilled" by the news.

The loved-up duo have been together since 2012 and they've already told their families about their pregnancy.

Another insider told the Mirror: "Daniel and Erin could not be happier to be expecting. They are absolutely thrilled, and can’t wait to become a family of three.

"They told their families and friends recently. It’s an incredibly exciting time."

Daniel and Erin met for the first time on the set of 'Kill Your Darlings', the biographical drama film.

The actor - who is best known for starring in the 'Harry Potter' film franchise - previously admitted that he and Erin are best friends.

He told Us Weekly: "I think that's the kind of relationship I always aspire to have with someone I'm in a relationship with. You want that person to be your best friend.

"In the case of Erin, we definitely are."

Daniel also discussed his approach to relationships and the world of modern dating.

He said: "I don't think you can ever control how anything starts.

"It's not like I seek out that way of meeting people or think I have to be their friend first but I think it's often a very natural thing to progress from into a relationship. The whole modern idea of 'friend zone' and all that stuff - that's a word I don't like very much."