Lloyds has become the first banking giant in the UK to ban its credit card customers from buying the rapidly devaluing digital currency Bitcoin.
The banking group, which also includes Halifax, MBNA and Bank of Scotland, fears customers could be left in debt after the cryptocurrency's value more than halved in just over a month.
The move follows warnings by regulators in the US, South Korea, China, Russia and India over the impact of the slide on investors, who had raced to buy Bitcoin during 2017.
- How far has Bitcoin's value risen and fallen?
- Why is Bitcoin controversial?
The digital currencies are independent of central banks and rely on encyption techniques to verify the transfer of funds.
But critics warn they are used by criminals and rogue states to carry out clandestine transactions.
- Who else has spoken out about Bitcoin?
US billionaire Warren Buffett has warned the boom will "come to a bad ending", while Germany and France have both called for tougher regulations.
Facebook has banned adverts for cryptocurrencies on its sites after criticism from users about scams and hoaxes promoted in their newsfeed.