Premier League soccer clubs have been warned by the U.K.’s Financial Conduct Authority (FCA) about sponsorship deals with unauthorized crypto firms.

The FCA said unauthorized firms could be breaching rules on financial promotions through the high-profile sponsorship deals.

Clubs enabling such promotions could be exposed to legal liability, money laundering and reputational damage, the FCA said. Companies not listed on the FCA’s crypto register are allowed to advertise in the U.K. only if their marketing material is signed off by a company authorized to approve it.

“Millions of football fans trust their club’s badge,” Lucy Castledine, director of consumer investments at the FCA, said. “Clubs should not let unauthorised financial firms…