WASHINGTON (AFP) ― U.S. police have foiled a plot to kill teen pop idol Justin Bieber and possibly castrate him with pruning shears, with the alleged killer promised $2,500 per testicle, legal documents revealed Thursday.

Mark Staake, 41, and his nephew, Tanner Ruane, were arrested in Vermont and New York last month and face charges in New Mexico of conspiracy to commit murder and conspiracy to commit aggravated battery with a deadly weapon.

The pair were allegedly plotting to strangle two victims and castrate them with pruning shears, but a convicted killer who is serving life in prison told police that the “ultimate” target was Bieber, who was performing in New York.

“Through follow-up investigation it was discovered that Justin Bieber may have also been a target of the murder plot,” said a statement by New Mexico’s Department of Public Safety.

An affidavit detailed the grisly plot, including the brand of pruning shears and how the testicles would be transported after the planned murders of two male victims in the northeastern state of Vermont.

The 18-year-old Canadian star’s managers said they took Bieber’s safety seriously. “We take every precaution to protect and ensure the safety of Justin and his fans,” a management official told AFP in an email.