Justin Bieber and Marg HelgenbergerJustin Bieber took to Twitter and slammed 'CSI: Crime Scene Investigation' star Marg Helgenberger who called the singer a 'brat' in an interview.

Bieber went on the offensive by posting tweets on the networking site and without naming Helgenberger he fired back, "Its kinda lame when someone you met briefly and never worked with comments on you. I will continue to wish them luck and be kind."

The 17-year-old singer continues, "I know who I am and sometimes people r just going 2 say what they want. Keep ur head up and be the man ur mama raised."

Bieber even called his alleged antics on the set of CSI a rumor saying, "Rumors are just that...rumors. In the end if you just be kind and be yourself people will know who you are. That goes for anyone I think."