Pop singer Justin Bieber has become the most followed person on Twitter, accumulating 33,326,624 followers on the social-networking site and passing pop queen Lady Gaga, the Twitter Counter Web site said.

The Canadian singer, who made headlines on Monday by posting a photo of his backside on Instagram, plans to release the 11-track album "Believe Acoustic" this year.

Lady Gaga was the first person to pile up more than 25 million followers on Twitter.

The other Twitter phenoms are Katy Perry, who is in third place with 31,484,156 followers, followed by Rihanna, Barack Obama, Britney Spears, Taylor Swift, YouTube, Shakira and Kim Kardashian.

The U.S. president, who has 26,168,542 followers, is the only person outside the world of entertainment who made the Top 10 list on Twitter. EFE