Frank Warren is locked in talks with the WBO after they refused to sanction Nathan Cleverly's light-heavyweight title defence against virtual unknown Robin Krasniqi.
It was announced this morning that the Welshman would go head to head with the Serb at the Royal Albert Hall on April 28.
However, WBO president Francisco Valcarcel has now issued a statement telling the 25-year-old's camp that the organisation will not sanction the bout.
"Francisco Valcarcel commented that the bout between Nathan Cleverly and Robin Krasniqi can't and won't be sanctioned," a statement read.
"Nathan Cleverly's fight with [Tommy] Karpency was sanctioned with the provision that the winner meet his mandatory opponent 120 days from the day of the bout."
A spokesman for the 25-year-old's promoter Frank Warren has confirmed that they are working to resolve the issue.
