Middleweight contender Julio Cesar Chavez Jr has tested positive for marijuana in the wake of his defeat to Sergio Martinez, according to a report.

RingTV.com cites inside sources, claiming that the fighter's test results showed traces of marijuana metabolites consistent with the use of the drug.

The Nevada State Athletic Commission will not receive the official results until "until Friday or Monday", and is unable to comment on the situation until then.

If found guilty of illegal substance usage, Chavez Jr could be fined for the entire amount of his $3 million purse and be hit with a year-long suspension.

"Top Rank is reviewing the situation," said a representative from the promotional company. "Julio Cesar Chavez Jr. will have an opportunity to explain about the situation to the Nevada State Athletic Commission."

Chavez Jr's official test results are yet to be released.