Canadian pop singer Justin Bieber
Canadian pop singer Justin Bieber arrives for amfAR's Cinema Against AIDS 2014 event in Antibes during the 67th Cannes Film Festival May 22, 2014. REUTERS/Benoit Tessier

Justin Bieber has spoken up at last. A new report claims that the young pop superstar has finally apologised for the racist joke he made when he was 15.

TMZ reported that the now 20-year-old singer is apologising, though partly blaming his age for the joke. Bieber told the celebrity news Web site that at a young age he didn't understand how words can hurt people.

"Five years ago I made a reckless and immature mistake and I'm grateful to those close to me who helped me learn those lessons as a young man," Justin Bieber tells TMZ.

"Once again....I'm sorry," Bieber concludes.

The racist joke has been made five years ago in a recently surfaced video wherein Bieber used the N-word, particularly pertaining to black people. The said video was published by British publication The Sun.

Reports claim that the video was shot as part of a concert documentary for "Never Say Never," and Bieber is said to have tried to buy the video for a large sum to keep it from the public, but to no avail.

Bieber has started his career at a young age, posting videos online of him performing. Information around the Web claims that Scooter Braun, a marketing executive, was the one who discovered the Canadian star.

Since Bieber's first album was released in 2009, which was certified platinum in the U.S., under Usher's record label, the young Canadian star has not stopped making a name. Fans all around the world has welcomed the new star openly, making Bieber's single "Baby" featuring Ludacris a hit, with more than a billion views on YouTube.

But the 20-year-old superstar's career has not been smooth sailing since he started gracing the headlines with negative news.

According to Daily Mail, the said racist joke may damage Bieber's career as it appears that the singer is currently signed to RBMG Records under the black singer, songwriter and "The Voice" coach Usher and has performed with several black artists throughout his singing career.

No reports yet on how Usher and other black artists close to the star react to the racist joke.