Ariana Grande and Justin Bieber have hit back at Tekashi 6ix9ine after he accused them of buying their number one spot on the US Billboard chart.

Ariana Grande

Ariana Grande

The rapper - who is on house arrest after he was jailed on charges relating to attempted murder, conspiracy to distribute heroin, and firearms-offences - insinuated that the pop stars purchased thousands of units of their charity collaboration, 'Stuck With U', to beat his track 'Gooba' to the top of the chart.

Taking to Instagram, he said: "Understand this, they bought 30,000 or so units on six credit cards.

"Six credit cards. Now again, you're gonna enjoy your No.1. Now explain how you buy 30,000 with six credit cards."

Ariana has penned a lengthy response, in which she insisted she and Justin - who are donating the profits from the track to the First Responders Children's Organisation - have their loyal fans to thank for the hit song landing No1.

And the '7 Rings' hitmaker told 6ix9ine to take a good hard look at himself for his attempt to "discredit hardworking women".

Part of her post read: "so with this celebration today, i would like to address a few things which i don't usually do (i don't give my energy to drama or strange accusations normally but this has gone a little too far) fans bought the song. JUSTIN'S fans bought the song. OUR fans bought this song (never more than four copies each, AS THE RULES STATE). they are ride or die mother***kers and i thank god every day that i have them in my life. not just when they fight for us to win (even when i ask them not to as i did this week) but because they're some of the greatest people i know. sales count for more than streams. u can not discredit this as hard as u try. to anybody that is displeased with their placement on the chart this week or who is spending their time racking their brain thinking of as many ways as they can to discredit hardworking women (and only the women for some reason.....), i ask u to take a moment to humble yourself. be grateful you're even here. that people want to listen to u at all. (sic)"

Ariana added that he should feel "blessed" that people want to listen to his music and to have achieved a top 5 hit.

The hip-hop star - whose real name is Daniel Hernandez - then recorded a video reaction and claimed it's wrong that people of a privileged position dominate the charts.

He said: "I speak for the millions of kids that come from nothing."

He then wrote: "You say for me to be humble. I don't think you know what humble is. YOU ARE VERY TALENTED AND BEAUTIFUL GOD BLESS YOU. (sic)"

Justin also had his say and insisted that 60,000 units were added at the last minute, whilst he reiterated what his collaborator said.

On his Instagram Story, he explained: "Nielsen company checks this and found all our fans are amazing and bought them.

"Don't discredit our fan base with false info."

The 'What Do You Mean?' hitmaker concluded that the most important thing is that the song is raising money for a "great cause".

He said: "This is my song with Ariana Grande and I'm honoured to work with her to raise money for a great cause.

"If you're going to say her name make sure you say mine because it's our song."