BOGOTA, February 8 (Reuters) - Colombian President Juan Manuel Santos's 2014 election campaign allegedly received as much as $1 million from Brazil's Odebrecht SA, the country's attorney general said on Tuesday, as fallout from a massive corruption scandal continued. A portion of some $4.6 billion allegedly paid by engineering company Odebrecht to Otto Bula Bula, a former Liberal Party senator, was designated for the Santos reelection campaign, Colombia's Attorney General Nestor Humberto Martinez said in a statement. "It has been established that of that amount, in 2014 Mr. Otto Bula sent two transfers to Colombia, which were cashed at the time, for $1 million, and whose final beneficiary was the campaign management of "Santos for President - 2014," he said. The president's campaign chief Roberto Prieto denied the accusation and Camilo Enciso, the president's transparency secretary, said the allegations were untrue. Telephone calls to Odebrecht in Sao Paulo went unanswered after hours. Bula, who was arrested last month on charges of bribery and illicit enrichment, was tasked by Odebrecht with ensuring a certain number of higher-priced tolls were included in a contract to build a highway, Martinez has said. Bula has denied those charges. The campaign of Santos's rival in the election, Oscar Ivan Zuluaga, is also being investigated for receiving money from Odebrecht. Zuluaga was the candidate for former President Alvaro Uribe's right-wing Democratic Center party. Odebrecht's reputation has been hit after prosecutors in Brazil unearthed a bribes-for-contracts scandal that has extended into other countries. U.S. prosecutors allege that Odebrecht paid hundreds of millions of dollars in bribes in association with projects in 12 countries, including Brazil, Argentina, Colombia, Mexico and Venezuela, between 2002 and 2016. Prosecutors in Peru on Tuesday asked a judge to order the arrest of former President Alejandro Toledo for suspected involvement.