The Pillow Talk star, who welcomed a daughter with girlfriend Gigi Hadid in September, was believed to be in New York, where he currently lives, when he went live on Instagram in the early hours of the morning.
Telling fans he was listening to tracks from his third studio album Nobody Is Listening, Zayn added: “I’ve recorded a sick song today. It might seem a bit weird. I just sat at a computer. I looped four bars. But that’s all I can say. It’s sick, right?”
As well as singing along to the tunes, Zayn swigged from a bottle of beer, ate pizza and smoked what some fans speculated was a cannabis joint.
“Why is Zayn getting high and blasting lights and music at 6am when he supposedly has a baby in the house?” one fan tweeted, while another added, “If he’s in NYC he went live at 6am, which seems an odd time to be smoking a joint and blasting music that loud.”
Zayn’s livestream came ahead of the official U.K. chart figures being released this Friday – with early predictions suggesting that Nobody Is Listening is due to enter the charts at number 10.