Mexico's top electoral agency says it will destroy ballots cast in the 2006 election and this year's vote.

The Federal Electoral Institute says its general board voted unanimously Wednesday to destroy all ballots in the presidential contests and other races. It says the ballots will be destroyed before the end of the year.

The agency says the high cost of storing and guarding ballots is one of the reasons it decided to destroy them.

Felipe Calderon was declared winner of the 2006 presidential election by less than 1 percentage point. Rival Andres Manuel Lopez Obrador claimed he was robbed of victory and demanded a full recount. Mexico's top electoral court rejected his request.

Lopez Obrador also finished second in this year's election in July, but by a wider margin.