Police in Los Angeles have launched an investigation into allegations comedian Jeff Dunham has been bombarded with online death threats.

The ventriloquist has allegedly been the victim of a hate campaign on Twitter.com, so police officers in L.A. obtained a warrant in a bid to track down the culprit, according to Tmz.com.

The website reports cops searched Twitter records in a bid to discover the identity of a user who allegedly threatened the star and his family.