Insane Clown Posse have been forced to switch venues for a planned Halloween concert in their native Michigan after local police raised security concerns about their fans.

The group recently launched legal action against officials at the Federal Bureau of Investigation (FBI) after its face-painted devotees, dubbed 'Juggalos', were added to the organization's National Gang Threat Assessment list.

Authorities claimed Insane Clown Posse followers exhibited thug-like behavior and undertook alleged criminal activity, with Juggalo-related crime being "sporadic, disorganized, individualistic" and involving "simple assault, personal drug use and possession, petty theft and vandalism."

The hip-hop duo, comprised of Violent J and Shaggy 2 Dope, has been fighting back at the label on behalf of fans, but the FBI classification is still causing the rappers grief.

Tour managers initially booked the Royal Oak Music Theater, near Detroit, for the stars' October 31st performance, but venue bosses decided to cancel the event this week after receiving advice from local cops.

A spokesperson for the Royal Oak Police Department tells TMZ.com they simply suggested theatre executives "reconsider" the booking because of "the type of crowd they (Insane Clown Posse) bring" and over concerns about available resources.

As a result, the rappers have relocated the Hallowicked show to The Fillmore in Detroit, insisting, "Halloween will not be spoiled."