Top Australian comic Hamish Blake is set to be a dad.

The radio and Tv star announced the happy news that his wife Zoe Foster is pregnant with their first child in his usual wacky style - by posting a picture of himself half-naked in a bath posing as a foetus in a sonogram scan.

Sharing the snap on Twitter.com, he writes, "Having baby with zotheysay! First ultrasound pic. Looks like me! Same undies! #prouddad"

He also confirmed the news on his hit radio show on Friday (01Nov13) with Andy Lee, saying, "I'm having a baby with Zo. That's a bit of big news."