By DAILY MAIL REPORTER
Threats: Rebecca Black, pictured in LA last week, is under police protection
Teen internet star Rebecca Black has been placed under police protection after receiving two disturbing death threats.
The 13-year-old, who has been dubbed the 'worst singer in the world', shot to fame earlier this year after heavily auto-tuned video of Friday went viral.
It has been viewed more than 110 million times on YouTube, attracting a
barrage of criticism.
'One of the threats came over the phone and another emailed,' Rick Martinez, a spokesperson for the Anaheim, California Police, told Radar Online.
'The threats were related to getting the music off the Internet or they would kill her. We are taking the threats very seriously.
YouTube hit: Rebecca Black's single Friday was viewed by millions
'Officers are keeping a watchful eye on her during this on-going investigation.'
The teenager has previously admitted she was shaken by the at times vicious comments she received online.
She told Good Morning America last month: '[The worst thing I've read was] I hope you cut yourself and I hope you get an eating disorder so you'll look pretty, and I hope you go cut and die.
'When I first saw all these nasty comments I did cry. I felt like this was my fault and I shouldn't have done this and this is all because of me. Now I don't feel that way.'
She sang the American national anthem to prove she could sing, and said she did not write the mocked lyrics.
Her mother paid $2,000 to the record label to produce the song and video, which was shot in her father's home with friends and family as extras.
'Those hurtful comments really shocked me. At times, it feels like I'm being cyberbullied,' she said.
Rebecca is reported to have earned in the region of $20,000, through YouTube's revenue-sharing plan, according to Forbes Magazine.
She's also estimated to have made thousands of dollars from iTunes sales.
Following an appearance on his radio show , Ryan Seacrest is also said to have introduced Rebecca to an A-list entertainment manager, to help take her career to the next level.
The cast of Glee are expected to perform a version of the single in an upcoming episode.