Australian singer David Campbell is celebrating after becoming a father to twins.

The star and his wife Lisa welcomed a boy and a girl, named William and Elizabeth, and he shared news of the birth by posting a picture of the babies on his Instagram.com page on Monday (12Jan15).

He added in a caption, "Hey guys. Here is William David Campbell and Elizabeth Ann Campbell. We call them Billy and Betty. Mum is wonderful. Leo is so excited and I am doubly in love."

The couple married in 2008 and they are already parents to a four-year-old son named Leo.