Justin Bieber has treated fans to a brand new song.

The Canadian has been teasing the track 'Heartbreaker' for months - but he has now finally unleashed it.

The tune marks the start of his 'Music Mondays' project, which will see the singer release a new song every week for ten weeks.

Speaking about 'Heartbreaker', Bieber said: "It's a song for people going through heartbreak - like I was when I wrote it. It means so much to me to be able to share what I was, and still am, going through, with my fans. I'm very proud of this song and I hope it gives my fans some insight into my heart."

His manager Scooter Braun meanwhile commented on Twitter: "All you can ask for is honesty. Why does he have such a connection with his fans? Because he is honest…"

'Heartbreaker' meanwhile is available to buy on iTunes now. Listen to 'Heartbreaker' below: