The US retailers Sears and Kmart have apologized and pulled from sale a T-shirt featuring the words “Ashli Babbitt American Patriot” after an outcry on social media.

Babbitt was shot dead by law enforcement while taking part in the attack on the US Capitol by a pro-Trump mob on 6 January. She had been inside the building and was attempting to climb through a broken window when she was shot.

After her death, her internet history showed she was a conspiracy theorist, including a believer in QAnon. Elements of the conservative movement have been attempting to make Babbitt a martyr for their cause.

After the T-shirt’s availability was brought to attention by a Twitter post from the Vox reporter Aaron Rupar, Sears tweeted a brisk apology from its official account, writing: “Thank you for bringing this product to our attention. This item is no longer available for purchase on Sears.com or Kmart.com.”

Both shops are owned by Transformco.

Last year, Walmart was found to be selling an All Lives Matter T-shirt on its website.

Both instances highlight concerns about third-party sellers: companies will sell items from external sources without vetting.

In June, the Wall Street Journal reported that Urban Outfitters and J Crew would open their digital stores up to third-party sellers, in a bid to compete with Amazon, which had been selling items by them for years.

In April, in a letter to shareholders, Amazon’s then CEO, Jeff Bezos, said that third-party sellers made up 60% of Amazon’s overall sales, compared with 34% in 2010 and 3% a decade earlier.

Last month, the first Capitol rioter to be sentenced, Anna Morgan Lloyd, got probation instead of a prison sentence.