Australian PM Scott Morrison has apologised for posting a video online after discovering its soundtrack - a famous hip-hop song - contained lyrics that were "just not OK".

The 11-second video showed government MPs raising their hands in parliament. In the caption, Mr Morrison praised his colleagues as being "on fire today".

But social media users widely expressed puzzlement over its accompanying song - Be Faithful, by US artist Fatman Scoop.

The song has several explicit lyrics.

The section posted on Mr Morrison's social media accounts was not explicit: "You got a hundred dollar bill, get your hands up! You got a 50 dollar bill, put your hands up!"

But the post was ridiculed as "bizarre" by people online. Many pointed out that the song, released in 1999, had explicit language and sexual references.

Some political observers said the post raised questions about whether Mr Morrison, who became prime minister three weeks ago, and his team were fully equipped for the top job.

But others dismissed such criticism as overblown, or saw a fun side.

The tweet was deleted about four hours after it was posted, and Mr Morrison apologised.