The Washington Capitals forward said he felt "absolutely terrible" for letting his club down and that he had "disappointed so many people that are close to me, including my family, team mates and friends".

The International Ice Hockey Federation (IIHF) confirmed Kuznetsov failed a test on May 26, the day Russia beat the Czech Republic to win the bronze medal at the World Championship in Slovakia.

The suspension rules the 27-year-old out of the 2022 Winter Olympic Games in Beijing but only applies to international matches.

Kuznetsov has not been banned by the National Hockey League (NHL).

The Washington Capitals said in a statement, however, that it would "remain in contact with the NHL as they determine the next steps", raising the possibility that the Russian may also be barred from representing his club.

The World Anti-Doping Agency has no jurisdiction over the case as the NHL is not a code signatory.

"Recently, the IIHF notified me that, due to a positive test for a banned substance, I would be suspended from international competition for four years," Kuznetsov said.

"I have made the decision to accept this penalty. 

"Representing my country has always been so close to my heart and something I take so much pride in. 

"Not being able to put that sweater on for four years is very hard to take.

"From the first day I took the ice in D.C., the Washington Capitals organisation and our fans have been nothing but great to me and my family. 

"I feel absolutely terrible for letting you down. 

"I realise that the only way I can win you back is to take ownership of my situation and my actions from this point forward."