George Zimmerman is preparing to put up his dukes for a celebrity boxing match.

The unconvicted killer of black teenager Trayvon Martin is giving one lucky person the opportunity to take a swing - all in the name of charity.

"It was my idea," Zimmerman said of the fight organised by former professional boxer Damon Feldman.

"Prior to the incident [Trayvon shooting] I was actually going to the gym for weight loss and doing boxing-type training for weight loss and a mutual friend put me in contact with Damon and provided me with an opportunity and motivation to get back in shape and continue with my weight loss goals and also be able to help a charity out."

In a newly released photo, Zimmerman is seen grinning while showing off his guns.

The 30-year-old former neighbourhood watch man, who identifies himself as Hispanic, says he is willing to fight anybody, black or white.

Feldman said: "We're not looking at it as a race thing ... We haven't discussed purple, yellow, white, black."

Although no opponent has yet been selected for the 1 March bout, Zimmerman is not short of offers.

Compton rapper The Game said that he's ready, able and willing to fight Zimmerman.

"I will beat the f**k out of him," the hip hop star told TMZ. "I would not be boxing for me. I'd be boxing for the legacy of Trayvon Martin and for his family.

"I would box him to knock him out...I would definitely take pleasure in it. It's legal, and I want to show him you can solve your disputes without a weapon."

In February 2012, Zimmerman followed and confronted Martin as he was walking through a gated community after visiting a convenience store in Miami, Florida.

The case sparked accusations that Zimmerman had racially profiled the 17-year-old before the shooting, with his acquittal in July 2013 sparking nationwide protests. Federal authorities are now reviewing the case to see if Martin's civil rights were violated.

The boxing match will be aired online and on Pay-Per-View.