Advertising rules were broken by a web page and a Facebook post from Arsenal football club, a watchdog said.
“The Advertising Standards Authority (ASA) said that the club had not done enough to show how risky the investment was.”
It said that “the ads can’t be shown again in the way they were.”
Arsenal said it would ask for an independent review of the decision, adding that the club had given information about the financial risks of the decision.
The fan tokens of some of the best football teams can be used to buy things.
Critics, including some fan groups, say that clubs that sell crypto fan tokens are encouraging people to invest in the risky and mostly unregulated world of cryptocurrency.