New York, Dec 27 (IANS): The largest police union in the US has urged online retailer Amazon to stop selling a controversial shirt related to the 'Black Lives Matter' protest movement.

Last week, the shirt, which carries the words "Bulletproof: Black Lives Matter", was removed from online sale by retailer Walmart after it received a complaint from the Fraternal Order of Police (FOP).

However, Amazon declined to comment and continues to sell the product, Xinhua news agency reported on Tuesday.

According to an open letter from FOP, the union said the shirt was "offensive" and appealed to Amazon Chief Executive Jeff Bezos to support it in "increasing the bonds of trust between the men and women of law enforcement and the communities they serve."

"Commercialising our differences will not help our local police and communities to build greater trust and respect for one another," Chunk Canterbury, president of the FOP, wrote in the letter.

"I write to urge you to prohibit the use of the Amazon name and website for the retail sale of these products," he added.

"Turning a buck on strained relationship will not contribute to the healing process," he said.

Canterbury described Amazon "as a pretty liberal marketer" and thought that the shirt might inspire violence against members of law enforcement, according to the Guardian.

The shirt was offered by Old Glory Merchandise, a third party vendor. Its owner Glenn Morelli told CNN that the shirt was not "a big seller at all" and that they don't like to offend anybody.

"You have to sell all different kinds of shirts. It's hard to make everybody happy," he added.