While Justin Bieber has become well-known for boozy nights out and getting in trouble with the law, he reportedly spent this weekend rather unusually for a pop star – getting baptised.

According to gossip website TMZ, the 20-year-old spent the past week studying the Bible with Hillsong NYC pastor Carl Lentz before being baptised in a friend's bathtub. He apparently chose the unique location after being unable to find a church where the ceremony could be conducted privately.

It follows a week of controversy for the star after two videos surfaced showing Bieber making racist jokes and substituting the lyrics to one of his hit songs with racist slurs.

Outrage following the videos' release forced Bieber to make a grovelling apology; stating that it was "a childish and inexcusable mistake".

"I am a man now who knows my responsibility to the world and to not make that mistake again," he added.

He then later posted an image from a book on his Instagram page, which features several Bible verses focussing on forgiveness and finding peace with God.

Despite his bad-boy image, Bieber has spoken about his faith numerous times, and enjoys a close relationship with Lentz, as well as lead pastor of The City Church, Seattle, Judah Smith, who apparently texts the him Bible verses each day.

The three have shared pictures of their time together on social media, and Bieber even posted a video of one of Lentz's sermons on his Twitter account, where he has over 52 million followers.

Lentz told CBN in March that the pop-star is "a good kid. He's trying to figure this out".

"People who are like, 'Is he even a Christian?' With Justin, I tell people grace and acceptance does not mean approval. I can accept you as a human being and not approve of your actions. That's how we've been loved. We love because we were first loved," he said.

"With Justin, it's not my job to be his police officer. It's my job to be a friend to him, and that's all I am.

Though Bieber has not yet confirmed reports of his baptism, he posted a short Instagram video of his family on Friday in which his shoulder tattoo reading "Your word is a lamp for my feet, a light for my path", a verse from Psalm 119, is clearly visible.