Hawaii Five-0 star Scott Caan is reportedly set to become a first-time father.

The actor's girlfriend, Kacy Byxbee, is pregnant with their first child, according to Life & Style magazine.

A source tells the publication that Byxbee's friend posted a photo of the mum-to-be's very pregnant belly with the caption "#babycaan" on Instagram.com.

Caan, the son of veteran actor James Caan, met his partner on the set of his hit Tv series.