Police say the calls were between Dana Martin, the 45-year-old prisoner accused of masterminding the plot, and one of the men he allegedly hired to carry out the gruesome plan.
In the tapes, Martin tells the nephew of a former jailhouse friend how to suffocate Bieber using a paisley scarf — apparently his signature move.
"Tie it really, really tight, knot it in the front once really tight, and put in a knot, and that cuts off the oxygen, and then tie it in the back again," Martin tells Tanner Ruane.
"That just seals the deal," he adds.
In another clip, he asks Ruane whether his uncle, Mark Staake, has gone over "the Bieber thing" with him.
"Nah, the way I like to work, dude, the way I work — I like to know as little as possible," Ruane replies.
At another point in the call, however, he tells Martin they have bought hedge clippers, which police have said the would-be killers were to use to castrate Bieber, his bodyguard and two other men unconnected with the star.
Authorities say Martin, who is serving two life sentences in a New Mexico prison for the killing of a 15-year-old girl, told them he had hatched the scheme after Bieber never returned messages he sent to the 18-year-old "Beauty and a Beat'' singer.
Police recounted in an affidavit filed late last year in a New Mexico court that Martin, who has a tattoo of Bieber on his leg, told them the perceived slight was part of what led him to dream up the alleged murder plot.
The promise of notoriety provided another incentive, police wrote in the affidavit.
They said Martin drew Staake into his scheme, and Staake brought in Ruane, his nephew and right-hand man.
Staake was released on probation at the end of October and started to track Bieber's whereabouts, Martin told police.
The murder was to take place in New York at the end of November, according to the affidavit, which was when Bieber was in the city to give a concert.
The plan was derailed when the accused would-be assassins accidentally ended up at the Canadian border.
The U.S. border agent found Staake had an outstanding probation violation warrant from New Mexico and he was arrested.
Martin and Ruane spoke on the phone later that day, and when Ruane told Martin that Staake had been arrested, Martin called off the plot.
In the phone call, which was recorded by authorities, Ruane expressed disappointment at Martin's decision, saying they had found one of the first two victims' homes and had brought a pair of hedge clippers for the castrations.
Staake and Ruane were arrested on charges of two counts each of conspiracy to commit murder and two counts each of conspiracy to commit aggravated battery.
The allegations against them have not been proven in court.
-By Paola Loriggio in Toronto