Former One Direction star Zayn Malik seems to have fallen out with collaborator Naughty Boy after branding him "a fat joke" in an online rant.
The singer, who quit the boyband earlier this year saying he wanted to be a "normal 22-year-old", has previously spent time in the studio with Naughty Boy prompting reports they were working on solo material.
The producer, real name Shahid Khan, put a track featuring Malik singing over an acoustic guitar online after he quit One Direction.
But today, Malik tweeted the musician saying: "You fat joke stop pretending we're friends no one knows you".
In another tweet that seems to refer to him, Malik said: "Someone learned how to upload a video... maybe now he should learn how to use logic ha you ain't s*** but a faker".
He is not the first person to fall out online with Naughty Boy - Malik's former bandmate Louis Tomlinson called him "inconsiderate" after he published the acoustic track online.
Earlier this year, Naughty Boy told Heat magazine that Malik had been under intense pressure and was in a studio with him because he wanted to enjoy time with his friend.
"I've been his friend. He needs one," Naughty Boy told Heat.
"Just because we were seen at my studio - you (don't) necessarily just make music. People seem to forget that he's under so much stress. Which is why he left the tour.
"There's a lot going on. People get caught up - what he has done is to be normal. Sometimes being normal is to try and sort things out with your fiancee or hang around with a friend. That is normal."