One Direction star Niall Horan is reportedly back on the market after splitting with underwear model Barbara Palvin.

According to The Sun, the Midnight Memories singer and Palvin - who are thought to have started dating at the end of last year - have parted ways due to the pressures of having a long-distance relationship and their hectic schedules.

An insider told the newspaper: "There was no big fall out, things just fizzled out as Niall and Barbara are both working in different parts of the world.

“They are both really busy and Niall is focused on recovering and getting ready for the band’s massive Where We Are tour. They are still in touch and friendly.”

While neither Horan or the Victoria's Secret angel are yet to directly comment on the reports, the model did fuel split speculation by posting an image of herself and a mystery man on Instagram.

She captioned the pic: "Early Valentine”, while Niall shared a snap of his new floppy blonde hair 'do.

The Irish heartthrob also wished his fans a Happy Valentine's Day, tweeting: "Happy valentines day my loves! Love you all ! Have fun! xxxx."