Naughty Boy thought Zayn Malik was hacked when he sent him an angry tweet.
The former One Direction singer tweeted his friend and producer calling him a "fat joke" and Naughty Boy admitted once he found out it was real, he was quite upset.
He told Fuse.tv: "I can deal with what he said but he knows the hate I've had to endure for him is the bit that upset me. That's not how I know Zayn to speak, even face to face. I definitely thought at first that he had been hacked."
Zayn originally wrote: "@NaughtyBoyMusic you fat joke stop pretending we're friends no one knows you.
"Someone learned how to upload a video... maybe now he should learn how to use logic ha you ain't s*** but a faker (sic)."
The messages were thought to refer to the snippet of a music video Zayn shot with Krept & Konan for his cover of 'No Type' which he reportedly believed Naughty Boy leaked.
Naughty Boy - whose real name is Shahid Khan - also hit out at Zayn for insulting his physique, saying he should know better because he has young fans.
He said: "The fat joke thing wasn't necessary and he's getting a lot of backlash for that because a lot of his fans don't look like Selena Gomez. At some point as an artist you have to take responsibility for everything you say. That's why I think Zayn did it out of anger."