Instagram has emerged as a shopping mall for a wide variety of fake consumer goods, from luxury handbags to designer sunglasses. But researchers recently discovered an even more blatant black market: counterfeit money and passports.

Numerous Instagram accounts seen by NBC News offered fake cash and forms of identification for sale, with many directing people to contact them through the encrypted messaging service WhatsApp. Both WhatsApp and Instagram are owned by Facebook.

The accounts posted pictures of what appeared to be stacks of cash, including U.S. and E.U. currency.

Instagram deleted the accounts after NBC News contacted the company for comment.

One such account, which went by the username “LegitMoney12,” also used the Instagram stories feature to promote duffle bags of cash with the caption “secure that money.” The account has over 3,000 followers and claims to be “100 percent reliable.” The account has since been deleted.

After some of the accounts were removed, simple searches of terms like “fake money” continued to turn up hashtags related to counterfeit currency and accounts that purported to sell fake money.

A screenshot of an Instagram account that claims to sell counterfeit money. Instagram

Eric Feinberg, an internet security researcher and founder of Gipec, a cyberintelligence company, said he came across the accounts after they were suggested to him by Instagram.

“This is the way Facebook and Instagram were designed,” Feinberg said. “The algorithms can be used for nefarious activity, whether it is the sale of illegal drugs, terrorism, hate speech and, now, counterfeit currencies.”

NBC News was unable to determine if the accounts had actually sold any counterfeit bills, but Feinberg said he was able to engage with the accounts over WhatsApp. The accounts answered Feinberg’s questions about authenticity and quality and claimed that the counterfeit currency was “Grade A” and could “bypass supermarket” detection, according to messages seen by NBC News.

One account asked for $240 for $1,000 of fake money.

The trade in counterfeit goods has risen in recent years, according to a March report from the Organisation for Economic Co-operation and Development, with fake name-brand footwear and clothing the most common goods.

Instagram has struggled to crack down on the sellers of counterfeit goods, who use the platform’s photo-focused network to show off their wares. In April, Ghost Data, a data analysis company, found more than 50,000 accounts engaged in counterfeit activities.

Other tech platforms have also had trouble stopping the spread of counterfeit goods. In April, President Donald Trump signed a memorandum meant to warn Amazon, eBay and the Chinese e-commerce company Alibaba about the issue.

The U.S. Secret Service, the federal agency charged with investigating counterfeit currency, declined to comment.

Tech companies including Facebook and Instagram have recently invested heavily in hiring security staff and contractors to crack down on a wide variety of issues including fake accounts, fraud, misinformation and hate speech.

Feinberg questioned whether the company was truly committed to removing counterfeits on its platform.

“Tell me why with 30,000 security staff they cannot find this activity,” Feinberg said.

Many counterfeit goods can be difficult to spot, since they closely resemble legitimate items for sale. The accounts selling counterfeit money, however, offered no such subtlety. One account used the hashtags #CounterfeitMoney and #CounterfeitMoneyForSale.

A screenshot of an Instagram account that claims to sell counterfeit money. The account was deleted after an inquiry from NBC News. Instagram

“Similar to luxury counterfeiters on Instagram, money counterfeiters use IG as digital showcase,” Andrea Stroppa, CEO of Ghost Data, said in an email.

Stroppa and his team found more than 119 profiles involved in the counterfeiting of money, passports and other forms of identification. The data revealed that many of the uploaded images were not original images, but copies of images elsewhere on the internet.

In a statement, a spokesperson for Instagram and Facebook told NBC News that the accounts were in violation of the company’s policies.

“We remove this content when we’re made aware of it,” the spokesperson said.

Some accounts claimed to sell legitimate fake currency for use in movies or as a way to show off on social media, while others claimed that their fake money could evade basic counterfeit detection techniques.

“The fact that the items (‘currency,’ in this case) are advertised ‘in the open’ doesn't make its purchase legal,” Shawn Henry, president of the cybersecurity company CrowdStrike Services, said in an email. “People need to know that purchase and/or possession of this illegal contraband carries serious criminal liability and heavy penalties.”