New details in the plot to kidnap and kill Justin Bieber have emerged, including a plan to castrate the pop star.

Audio of phone calls made last November from a prison near Las Cruces, N.M., released today reveal the details of the grisly plot.

Police told ABC News' Albuquerque affiliate KOAT that inmate Dana Martin, who is doing time at the Southern New Mexico Correctional Facility for the murder and rape of a 15-year-old girl, was the mastermind behind the plot.

Police said he directed a former jailhouse friend in Vermont, Mark Staake, and Staake's nephew, Tanner Ruane, to carry out the kidnapping and murder.

"Did he go over the Bieber thing with you?" Martin asked Ruane in a taped phone conversation.

"Nah. The way I like to work dude, I like to know as little as possible," Ruane replied in the recording. "He's gonna use one of the things you gave him, and then he's gonna take care of it."

Authorities at the correctional facility said "take care of it" is the same as murder.

But that's not all the men allegedly planned to do.

"We went and bought the hedge clippers," Ruane was heard saying on the audio recording. "You're gonna give me 5 large ($5,000) for each one I get."

Police said the men planned to use the clippers to castrate Bieber and his bodyguard in New York City.

Martin also allegedly instructed the men to suffocate their victims with his signature paisley scarf.

"Tie it really tight, and that cuts off all the oxygen, and then tie it in the back again, really tight. That seals the deal," Martin said in a taped phone conversation.

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But before Staake and Ruane could travel from Vermont to New York to "seal the deal," the two were arrested by border patrol agents after making a wrong turn into Canada.

They, along with Martin, now face two counts each of conspiracy to commit murder and two counts each of conspiracy to commit aggravated battery.

According to a New Mexico State Police affidavit, Martin, who was sentenced to 978 years in jail for rape and murder in 2000, had an image of Bieber tattooed on his leg and plotted to kill him after his attempts to contact the 18-year-old pop star failed. The affidavit also alleged that Martin orchestrated the plot to achieve notoriety.

After details of the foiled plot were first revealed in December, a representative for Bieber released this statement to ABC News: "We take every precaution to protect and ensure the safety of Justin and his fans."

ABC News' Vania Stuelp contributed to this report