Elton John paid tribute to George Michael on social media.

Michael passed away at his home on Christmas Day at the age of 53.

John posted a picture of himself alongside Michael on Instagram.

The caption below read, "I am in deep shock. I have lost a beloved friend - the kindest, most generous soul and a brilliant artist.

My heart goes out to his family and all of his fans. @GeorgeMichael #RIP."

The two artists famously collaborated on "Don't Let the Sun Go Down On Me," in 1992.

The song reached the top of the charts in both the US and the UK.