(Reuters) -Chelsea forward Mykhailo Mudryk has been charged with anti-doping rule violations after a sample taken last year produced an adverse finding for a prohibited substance, England's Football Association (FA) said on Wednesday.

Mudryk had confirmed in December that a urine sample had produced the adverse finding following a routine anti-doping test, which the Ukraine international said came as a "complete shock" as he had never knowingly used a banned substance.

The 24-year-old, who joined Chelsea in January 2023 for an initial fee of 62 million pounds ($83.44 million), had been provisionally suspended and has not played since.

"We can confirm that Mykhailo Mudryk has been charged with Anti-Doping Rule Violations alleging the presence and/or use of a prohibited substance, in terms of Regulations 3 and 4 of The FA's Anti-Doping Regulations," an FA spokesperson told Reuters.

"As this is an ongoing case, we are not in a position to comment further at this time."

The regulations deal with the presence of a prohibited substance or its metabolites or the use or attempted use by a player of a prohibited substance or a prohibited method.

Mudryk risks a four-year ban if he cannot establish that the anti-doping rule violation was not intentional.

Reuters has contacted Chelsea but the club has not commented on the charges.

($1 = 0.7431 pounds)

(Reporting by Rohith Nair in Bengaluru;Editing by Toby Davis)