Sergey Kovalev's failed drug test forces cancellation of Jan. 30 fight with Bek Melikuziev

One of boxing's top events in early 2021 is officially canceled.

The Jan. 30 bout between former light heavyweight champion Sergey Kovalev and Bek Melikuziev has been nixed after Kovalev failed a drug test because of banned substances, Golden Boy Promotions announced on Friday.

Kovalev was informed earlier this week that his A sample submitted to the Voluntary Anti-Doping Association on Dec. 30 yielded external testosterone and metabolites, according to test results obtained by ESPN.

Golden Boy, which promotes Melikuziev, said in a statement Friday that the California State Athletic Commission determined the bout must be canceled.

"While we are crushed for [Melikuziev], we know that he will nevertheless have a tremendous year in 2021," Golden Boy said in the statement.

On Thursday, Kovalev's promoter, Main Events CEO Kathy Duva, said the former champion has proved to be a clean fighter throughout his career and that he "maintains that he did not purposefully ingest any banned substances."

Duva also said the company is planning on having his B sample tested by VADA. However, it appears those results will no longer have any bearing on a potential fight against Melikuziev (6-0, 5 KOs), one of boxing's rising prospects.

The January bout was positioned to be a pivotal fight for Kovalev (34-4, 29 KOs) at this point in his career. The 37-year-old hasn't fought since November 2019, when he suffered an 11th-round knockout loss to Canelo Alvarez.