LONDON — Britain’s tax watchdog has seized three non-fungible tokens, in what is thought to be the first seizure of NFTs by a U.K. law enforcement agency.

Officials at Her Majesty’s Revenue and Customs say they seized the NFTs during an investigation into a suspected value-added tax (VAT) fraud case worth £1.4 million ($1.9 million).

According to HMRC, the suspects tried to recover more VAT than they were due using stolen identities and unregistered phone numbers. They also used false invoices to conceal their identities. According to HMRC, the scheme included 250 fake companies.

Nick Sharp, HMRC deputy director for economic crime said Monday that the first seizure a Non-Fungible Token was a warning to those who believe they could use cryptoassets as a way to conceal money from HMRC.

Sharp said, “We adapt constantly to new technology in order to ensure that we keep up with how criminals or evaders seek to conceal assets,” Sharp continued.

NFTs can be described as unique digital assets that track the ownership of virtual goods, like works of art and characters in video games, via blockchain. Blockchains underpin all major crypto currencies.

NFTs are in high demand. In fact, sales have surpassed $40 billion for these tokens since 2016. But the market is prone to thefts and scamsThere is concern that market manipulations such as wash-trading may have fuelled a large amount of NFT trading.

HMRC states that it was the U.K.’s first law enforcement authority to take NFTs into its possession. Authorities seized three NFTs representing digital art, as well as another £5,000 in other crypto assets. HMRC stated that the investigation is still ongoing and that three NFTs representing digital art are being inspected.