Ariana Grande insists reported nude pictures of her are fake - because her bottom is "a lot cuter" in real life.

The ‘Problem’ hitmaker took to her Twitter account to address rumours that a selection of naked photographs leaked onto the internet are of her and she laughed off the claims by joking she is "praying for" anyone who thought they were her.

"but forreal tho whoever thought those were actually me...... love u but I'm praying for u (sic)"

The brunette star - who is currently dating 26-year-old rapper Big Sean - is not the only one to deny the leaked nudes are real, with fellow Nickelodeon star Victoria Justice also claiming that photos of her are fake.

The refutation comes days after an unidentified hacker stole explicit images and videos of more than 100 celebrities from Apple’s iCloud service and published some to photo-sharing website 4chan.

Other celebrities affected by the scandal include Jennifer Lawrence and Kate Upton, who have confirmed the images of them are real, but are warning that they will take legal action against anyone who publishes them.

On Monday, the FBI confirmed in a statement that an investigation to find the hackers responsible for the material has begun.

The statement read: "The FBI is aware of the allegations concerning computer intrusions and the unlawful release of material involving high profile individuals, and is addressing the matter. Any further comment would be inappropriate at this time."