Prime Minister Scott Morrison's personal website has been taken over and now plays a lewd rock song called "Scotty Doesn't Know".

An internet troll is taking responsibility for claiming the website scottmorrison.com.au after the domain licence lapsed overnight.

"So, the PM forgot to renew his website and it expired today ... Most fun I've had with $50 in a long time," Jack Genesin wrote on Facebook.

The website "take-over" has been active for more than 12 hours.