A source has told Page Six that BTS are working with Justin Bieber on a new song. The news comes after BTS' label HYBE (previously known as Big Hit Entertainment) bought Scooter Braun’s Ithaca Holdings company earlier this month.

The source said, "They are taking their time on it and going to make sure it is released right."

Earlier this week BTS announced their second English single "Butter", which will land next month. It'll follow their huge English hit "Dynamite" that dropped in August last year, which recently became the longest-charting song by a Korean act on the Billboard Hot 100, overtaking PSY's 2012 hit "Gangnam Style".

This month Bieber followed up his JUSTICE album with his surprise Freedom EP.

BTS' "Butter" single will be released 21 May.