Peru.21 said it had received audio tapes of private conversations in which businesswoman Carmen Rosa Nunez offered up to 700,000 soles, nearly $250,000, to be designated as the National Solidarity party's second vice presidential candidate in the April 10 election. The identities of the people with whom she talked were not known.

The newspaper, which didn't say who sent it the tapes to, printed a transcript, and the audios have since been disseminated by other media and on the Internet.

Castaneda, who has said little publicly during his campaign, did not comment on the newspaper's claims.

Nunez and National Solidarity activists denied she paid for her nomination, charging that the audios were part of an "dirty war" attempt to undermine Castaneda.

"National Solidarity has never traded or received money or contributions in return for legislative positions on its election lists or for the presidential post - this we flatly reject," Rep. Walter Menchola, a party member, told Canal N cable television.

He also said Nunez had not contributed financially to the party's campaign.

Menchola charged that the tapes had been manipulated and edited to do "political damage" to Castaneda.

While she disputed the charges, Nunez said Wednesday that she was willing to give up the nomination.

Political parties have until Monday to register their candidates for Peru's presidency and two vice presidential posts.

According to the latest survey by the Apoyo polling firm, Castaneda and former President Alejandro Toledo are each supported by about 23 percent of likely voters. Keiko Fujimori, daughter of jailed former President Alberto Fujimori, is at 20 percent.