Canadian pop star Justin Bieber and the co-writers of the no 1 hit Sorry are being sued over alleged copyright infringement, according to Reuters.

Indie artist Casey Dienel, who performs under the name White Hinterland, accused Bieber of using "specific and unique characteristics of the female vocal riff" from her song Ring the Bell without permission. Her song came out a year before Sorry.

Dienel claims the vocal riff in Ring the Bell is “virtually identical” to the tune sampled in the first eight seconds of Sorry.

Even The New York Times had noted similarities between the two songs in an article titled "25 Songs That Tell Us Where Music Is Going" that was published on March 13, according to Dienel.

Dienel said she has contacted Bieber in an effort to find a resolution, but he allegedly “ignored” her and refused to talk.

The lawsuit that was made public on Thursday seeks unspecified damages, including profits from Bieber’s smash hit.

Sorry has more than one billion views on YouTube.