The Danish Lego group reacted indignantly to a kit that makes a Glock pistol look like a Lego toy.
In an advertisement published on Instagram in June, the US company Culper Precision, which specializes in weapon conversion, speaks of a "childhood dream come true."
In a letter, Lego asked the US company to stop producing the red, blue and yellow panels for handguns immediately.
The organization Mums Demand Action, which campaigns for stricter gun laws in the United States, has reportedly made Lego aware of the action.
The idea of disguising guns as toys while children die from guns is just "sick," said the organization's founder, Shannon Watts, of the Washington Post.
Weapon marketed as "Block 19"
Culper Precision had marketed the Lego-style weapons as "Block 19", based on the pistol from the Austrian manufacturer "Glock 19" - for prices between 549 and 765 dollars (466 to just under 650 euros).
In the advertising, which has since been deleted, it said: »Guns are fun.
Shooting is fun.
30 bullets fully automatic are fun «.
"It's irresponsible and incredibly dangerous," Watts tweeted.
This year alone, children accidentally fired gunshots 165 times, said Watts, referring to figures from the Everytown organization.
Last year 142 people died from accidental shots by children or minors.
The head of Culper Precision, Brandon Scott, confirmed the Washington Post that he had received the letter from Lego.
His company decided to comply with the request.
According to him, the company had sold fewer than 20 of the weapons.
hba / AFP