The reality TV star has been slammed for promoting an untested cryptocurrency on Instagram.
Kim asked her 250 million followers to speculate on crypto tokens by promoting an advert for Ethereum Max.
The head of the UK’s Financial watchdog said influencers fuel the “delusions of quick riches”
Charles Randell called it “a speculative digital token created a month before by unknown developers”.
Mr Randell was speaking to the Cambridge International Symposium on Economic Crime.
The FCA chairman said the post may have been the “financial promotion with the single biggest audience reach in history”.
“I can’t say whether this particular token [Ethereum Max] is a scam,” he said.
“If you buy them, you should be prepared to lose all your money.”
Mr Randell said there was a case for regulation of promotions to address consumers’ misconceptions and “often misleading advertising techniques of some crypto businesses”.