Elton John is set to perform at the funeral of George Michael like he did Princess Diana, says a friend.

The Daily Star reports that the Rocket Man singer ‘will sing as he did for Diana’s funeral as a final farewell,’ according to an insider.

Openly gay Outside singer George passed away in his home on Christmas Day. His cause of death is yet to be confirmed.

The comments follow Elton’s heartfelt tribute to his friend on Instagram over the festive period.

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, friends and all of his fans. @GeorgeMichael #RIP A photo posted by Elton John (@eltonjohn) on Dec 25, 2016 at 3:24pm PST

The insider is quoted as saying: ‘There will be so many mourners and friends. It will be the biggest funeral since George’s mate Di’s.’

Elton and George scored a huge worldwide hit together in 1991 with an updated version of Elton’s song Don’t Let the Sun Go Down on Me.

Elton also scored the biggest-selling single of all time when re-released Candle in the Wind. The song was furthermore a tribute to Princess Diana after her death in 1997.

Elton and also George’s publicists have been contacted for comment.

The reports follow resurfaced quotes from George Michael about Elton in an interview for The Guardian.

In it, George said: ‘He [Elton] will not be happy until I bang on his door in the middle of the night saying, ‘Please, please, help me, Elton. Take me to rehab.’ It’s not going to happen.’

He added: ‘You know what I heard last week? That Bono … Oh for God’s sake … Geri [Halliwell] told Kenny that Bono, having spoken to Elton, had approached Geri to say, ‘What can we do for George?’ This is what I have to deal with because I don’t want to be part of that social clique. All I’d have to do to stop it is hang out in London, so people realise I don’t look close to death