George Zimmerman selling gun he used to kill Trayvon Martin in 2012

Trayvon Martin was shot by a white man as he walked down the street in a gated community on February 26, 2012 in in Orlando, Florida.

The gun used to kill unarmed black teenager Trayvon Martin in 2012 in the United States has gone on sale on a new website, after an online auction website rejected to sell it.

"Our site rules state that we reserve the right to reject listings at our sole discretion, and have done so with the Zimmerman listing," according to a statement posted Thursday by GunBroker. "We want no part in the listing on our web site or in any of the publicity it is receiving."

George Zimmerman is now trying to sell the weapon through United Gun Group, an online marketplace for firearms. The gun went on sale for $5,000, generating a series of denunciations.

"I am honored and humbled to announce the sale of an American firearm icon," Zimmerman said in a post said. "The firearm for sale is the firearm that was used to defend my life and end the brutal attack from Trayvon Martin on 2/26/2012."

On February 26, 2012, the 17-year-old Martin was shot dead by Zimmerman in Orlando, a suburb of the city of Sanford, Florida.

The shooting sparked mass protests across the US and intense discussions over race relations in the country because Martin was unarmed when he was shot by Zimmerman.

In June 2013, a six-woman jury in Florida has said that Zimmerman’s fatal shooting of the unarmed teenager was justified, and acquitted him of second-degree murder and manslaughter.

After the controversial verdict, tens of thousands of Americans staged rallies across the country to protest the acquittal.

George Zimmerman in court in July 2013, in Sanford, Florida. (Getty Images)

A crime scene technician shows the gun used by George Zimmerman to shoot Trayvon Martin during Zimmerman's trial in 2013. (EPA photo)

Zimmerman said he plans to use the profit from the sale of the weapon to fight Black Lives Matter, a movement which was formed in 2013 after his acquittal over the shooting.

He maintains that he shot dead Martin in self-defense. But the teenager’s family said he was simply passing through the residential area on his way home. The incident has made the boy a symbol of racial profiling in the United States.

Large-scale protests were held across the US last year after a series of high-profile incidents of white police officers killing unarmed African-American men, most notably Michael Brown in Ferguson, Missouri; Tamir Rice in Cleveland, Ohio; Eric Garner in Staten Island, New York, Walter Scott in North Charleston, South Carolina, and most recently Freddie Grey in Baltimore, Maryland.

George Zimmerman is auctioning off the pistol used in the fatal shooting of Trayvon Martin. Photo / AP

The pistol former neighborhood watch volunteer George Zimmerman used in the fatal shooting of Trayvon Martin is going up for auction online.

In an interview with Orlando, Florida, TV station WOFL, Zimmerman said he had just gotten the pistol back from the U.S. Justice Department, which took it after he was acquitted in Martin's 2012 shooting death.

"And I thought it's time to move past the firearm," Zimmerman told the station. "And if I sell it and it sells, I move past it. Otherwise, it's going in a safe for my grandkids and never to be used or seen again."

The auction listing on GunBroker.com lists the gun as a 9 mm Kel-Tec PF-9 pistol. The auction begins Thursday at 11 a.m. EDT and the bidding starts at $5,000.

The auction listing also says a portion of the proceeds will go toward fighting against violence by the Black Lives Matter movement against law enforcement, combatting anti-gun rhetoric of Democratic presidential candidate Hillary Clinton and ending the career of Angela Corey, who led the prosecution against him.

Zimmerman has said he was defending himself when he shot and killed Martin, an unarmed black 17-year-old. The shooting sparked protests and a national debate about race relations.When asked what he thought of people who would be opposed to auctioning the gun, Zimmerman said: "They're not going to be bidding on it, so I couldn't care less about them."

"The Trayvon Martin Foundation is committed to its mission of ending senseless gun violence in the United States," read a statement an attorney for Martin's family gave the Florida station. "This election season, we are laser focused on furthering that mission. As such, the foundation has no comment on the actions of that person."

Zimmerman said he has received death threats but has decided not to cower.

"I'm a free American," he said. "I can do what I want with my possessions."