The Venezuelan opposition rejected President Hugo Chavez's victory in a referendum over his mandate Monday and said they would contest the outcome.

"We firmly and categorically reject the result ... we're going to collect the evidence to prove to Venezuela and the world the gigantic fraud which has been committed against the will of the people," opposition leader Henry Ramos Allup told a news conference.

Two of the five National Election Council (CNE) directors announced they disagreed with the results because the ballots had not been properly audited.

"One cannot consider as official the partial results which partof the CNE leadership wants to announce," said Sobella Mejia, one of the council's officials.

The CNE had announced earlier that President Hugo Chavez won a referendum on his mandate with 58.25 percent of the electorate voted for him to remain in office.