Amazon vowed to crack down on coronavirus profiteering. Some sellers have figured out loopholes.

Amazon took a hard line against pandemic profiteering last month, vowing to remove product listings that claim to prevent the coronavirus.

But third-party merchants that sell millions of items on the e-commerce giant's marketplace are already finding ways around that. The latest gambit: promising coronavirus protection in the gallery of images that shoppers see next to the product on the site.

A photo hawking Lutos Advanced Hand Sanitizer claims that it will "protect you from COVID-19," without making the claim in the product description. Agelloc Hand Sanitizer Soothing Spray promises "efficient prevention of coronavirus" in a photo, too.

Avoiding spelling out the claims in the text helps sellers skirt algorithms trained to scan and delete products that break the rules.

Consumers' trust in Amazon makes that marketing particularly hazardous, said Svetlana Ilnitskaya, director of customer strategy of Incopro, a firm that helps brands protect themselves from intellectual property and copyright theft.

"The claims are false and it's really a dangerous place for consumers," Ilnitskaya said.

Messages from the seller accounts for the Lutos and Agelloc products said the products were aimed at helping consumers stay safe. Neither merchant, nor several others making assertions about preventing the coronavirus, commented on using photos to make those claims.

Amazon removed the product listings after The Washington Post asked about them. The company requires sellers to provide accurate information, and it has developed digital tools for the coronavirus outbreak "to scan the hundreds of millions of product detail pages for any inaccurate claims our initial block may have missed," spokeswoman Cecilia Fan said in an emailed statement. All told, Amazon has blocked or removed more than 6.5 million products, she said.

(Amazon chief executive Jeff Bezos owns The Washington Post.)

Amazon has struggled for years to police its marketplace. That's in large part because third-party merchants, not Amazon itself, account for the majority of physical merchandise sold on the site. That amounted to as much as 58 percent in 2018, Bezos wrote in a letter to shareholders last year.

The company routinely grapples with a scourge of counterfeit products, so much so that the Trump administration announced plans in January to begin imposing fines and other penalties on merchants, warehouses and e-commerce marketplaces such as Amazon that facilitate the import and sale of counterfeits. The company forbids the sales of cannabidiol on the site, but creative sellers have figured out how to bypass Amazon's detection, making CBD products easy to find. Former executives have said the company prioritizes selection over preemptively blocking merchants who might violate rules.

Since the outbreak began, Amazon has worked to police rogue sellers who engaged in price gouging on vital items such as face masks. And the company has struggled to keep pace with the flood of orders from shoppers leery of venturing out of their homes during the pandemic.

In February, Amazon warned sellers about "false claims in regards to COVID-19," and said then it had blocked or removed more than 1 million products for suspect or misleading claims. The company also stopped letting sellers bid on the words "coronavirus" or "covid-19" as a keyword in search results. In mid-March, the company said it suspended more than 3,900 selling accounts in its U.S. store for violating its fair pricing policies.

Despite those measures, sellers have sidestepped Amazon's detection for coronavirus-protection claims with images that run along their products. The seller of Flightbird Disposable Hand Sanitizer Gel, for example, included an image that claims the product "effectively inhibits new coronavirus."

In a message, that seller said "the product effectively keeps hands clean."

Just as the coronavirus pandemic is exposing cracks in society - everything from sick leave for gig workers to Internet inequality for digital learning - it's also highlighting the shortcomings of Amazon's limited vetting of sellers on its platform, said Juozas Kaziukėnas, chief executive of the e-commerce research firm Marketplace Pulse. The company requires sellers to submit business documents, among other items, to get on the platform. But the ability to obtain those can vary by country, and that's allowed some dubious international sellers on Amazon's U.S. e-commerce site, Kaziukėnas said.

"The coronavirus has resurfaced a bunch of issues we've seen about Amazon in the last several years," Kaziukėnas said.

Amazon's Fan said the company's vetting process uses "a proprietary system that analyzes hundreds of unique data points to identify potential counterfeit or infringement risk."

Consumers, desperate to acquire hand sanitizer, haven't been kind to the off-brand products on Amazon that have made coronavirus claims. Some of the listings were so new they didn't have customer reviews. But one review for a hand sanitizer from Wenasi called the product "terrible" and added that bottle appeared to have already been used by someone. Another reviewer was even more blunt: "This is pandemic profiteering plain and simple."

Amazon has proved to be a crucial piece of the retail economy during the pandemic when consumers shop from home to avoid the possibility of spreading the coronavirus. The surge of orders has so overwhelmed Amazon that it's racing to hire 100,000 people to work in its warehouses and deliver its packages. And its third-party sellers augment Amazon's supplies, even though it still remains difficult to find brand-name toilet paper and sanitary wipes on the site.

Even employees at Amazon warehouse across the country have decried the shortage of hand sanitizer, and other cleaning products, as they've raised alarms about unsafe working conditions. Workers in at least 21 warehouses and shipping facilities have tested positive for covid-19.

Amazon's Fan said the company is aggressively rooting out sellers engaged in bogus claims, price gouging and abusing its marketplace.

"When we find a bad actor, we close their account, any related accounts they may be using, and constantly monitor new accounts to ensure they are not related to a previously detected bad actor," Fan said.

Still, they persist. Another selling tactic to win over customers: using the branding of trusted products. The picture for a pump bottle of hand sanitizer that Kitt Amino Acid sold was nearly identical to Purell's Soothing Gel product that's out of stock on the site. One difference, the word Jaysuing, the product brand, is in the spot where Purell's name normally would be.

The Food and Drug Administration regulates hand sanitizers in the United States as an over-the-counter product, and because of those regulations, Purell's parent company, Gojo, recommends consumers "purchase hand hygiene products from responsible and reputable companies," company spokeswoman Samantha Williams said. While the company is aware of Jaysuing products on Amazon, it hasn't contacted Amazon to remove them, she said.