The Justin Bieber murder plot phone call has been released.

Convicted criminal Dana Martin's conversation with a hit man has been made public in which the pair can be heard plotting to kidnap the 18-year-old singer last November in order to castrate and strangle him, with a $2,500 bounty on each of Justin's testicles.

The recording, obtained by KOAT 7 News in Albuquerque, was made from a Las Cruces prison last November - where Dana is serving two life sentences for raping and killing a 15-year-old girl - and he can be heard going over the plan to kidnap Bieber and his bodyguard with hit man Tanner Ruane as well as discussing former inmate Mark Staake, who was allegedly roped in to execute the murder.

Tanner - who is currently being investigated for conspiracy - says, "The way I work, dude, is I like to know as little as possible. [Mark]'s going to use one of the things you gave him to get him out of this, he's gonna go take care of it. We went and we bought some hedge clippers. You're gonna give me five large for each one I get."

"He's gonna kill the pitbulls and then you're gonna castrate them," Dana replies.

TMZ are reporting "pitbulls" was the code word for the Canadian singer and his security. The plan was to strike in New York when Justin was performing at Madison Square Garden and strangle the teen idol with a paisley tie, but only after they had removed his genitals with garden shears.

Dana then goes on to explain how to best kill Justin using his signature move, saying, "Tie it really, really tight. Knot it in the front once, really tight, put it in a knot. That cuts off the oxygen, and then tie it in the back again, really tight. That seals the deal."

Justin was spared after the murderer - who has a tattoo of the "Boyfriend" singer on his leg - let slip his intentions to prison wardens.