Fast fashion giant Shein said that it was conducting an investigation after a product on its website featured what appeared to be an edited image of Luigi Mangione, the man accused of killing UnitedHealthcare’s CEO last year.

Mangione is facing the death penalty in federal court after allegedly gunning down UnitedHealthcare CEO Brian Thompson in Manhattan in December.

He has been indicted for murder and other charges related to the death, but he has pleaded not guilty to all federal and state charges against him.

Shein said in a statement to CNN that the image was provided by a third-party vendor and has been removed.

In the photo, the Mangione figure models a short-sleeved button-down shirt with floral patterns.

It cost US$11.69 ($17.87) and was sold out in multiple sizes, according to a screengrab from the Wayback Machine, a digital archive of the internet.

It’s unclear if artificial intelligence was used to manipulate the image.

“We have stringent standards for all listings on our platform,” a Shein spokesperson said in the statement.

“We are conducting a thorough investigation, strengthening our monitoring processes, and will take appropriate action against the vendor in line with our policies.”

The image quickly began circulating on social media, including on popular pop culture accounts like Pop Crave.

Mangione has amassed a cult following, mostly fuelled by the American public’s frustration with the health care system and insurance industry.

At protests, people have held ‘Free Luigi’ signs in support of him, and the UPenn graduate has received hundreds of letters from around the world.

For some, he’s even emerged as a sort of anti-hero heartthrob.

Prosecutors earlier this year raised concerns over heart-shaped notes hidden in his socks.

Officials, meanwhile, have described the killing as a “frightening, well-planned, targeted” and “cold-blooded” murder.