The World Boxing Council said that welterweight champion Lloyd Honeyghan's victory over Johnny Bumphus on Sunday was not a title fight because the WBC had not sanctioned the bout.
"The main reason for our refusal to sanction it is that it was scheduled for 15 rounds, which goes against the measures for medical security of our organization," the WBC said in a statement.
The WBC, unlike other boxing organizations, limits its championship fights to 12 rounds.
Honeyghan gave up his World Boxing Assn. title, saying he did not want to fight the WBA's top-ranked contender, South African Harold Volbrecht. Honeyghan, who is black, said he was protesting South Africa's policy of racial separation.
Mark Breland beat Volbrecht earlier this month to win the vacant WBA title.