Justin Bieber's mother has admitted that her son's maturation has been something of a "whirlwind".

The singer has gone through many of his teenage years in the public spotlight and this means any negative behaviour is scrutinised.

This year has particularly been a difficult one for Bieber and his new film Believe examines the person behind the headlines.

Speaking to MTV, the singer's mother Pattie Mallette said that she is strapped in for the ride when it comes to seeing her 19-year-old become an adult.

She said: “It's really fun watching him grow and transition. It's just been this crazy whirlwind, and I'm just along for the ride."

Believe, however, seemingly bombed at the US box office, taking in $4.5 million during its first five days. Watch a trailer for Believe below: