The estate of late pop star Prince has rebuked Donald Trump after the president used one of his songs at a rally, despite previous warnings not to.

Purple Rain was played at a Trump event in Minneapolis, Minnesota, on Thursday, with Prince's estate saying that violated an agreement made in October 2018.

The estate shared a legal letter apparently from the president's campaign, which said it would no longer use the music.

Alongside the note, the official Prince Twitter account wrote: "President Trump played Prince's Purple Rain tonight at a campaign event in Minneapolis despite confirming a year ago that the campaign would not use Prince's music.

"The Prince Estate will never give permission to President Trump to use Prince's songs."

Purple Rain was played over the loudspeakers at The Target Center in Prince's hometown of Minneapolis. The Trump campaign has been contacted for comment.

This is far from the first time the campaign has been warned off the unauthorised use of music.

Artists including Rihanna, Pharrell Williams and Aerosmith front man Steven Tyler have criticised the president for using their tracks.