Colombia's chief prosecutor said Thursday that he was opening preliminary investigations into the contacts a U.S. consultant and three other foreigners have had with leftist rebels.

The prosecutor, Mario Iguaran, also asked the Supreme Court to investigate three opposition Colombian lawmakers, including Sen. Piedad Cordoba, who helped Venezuelan President Hugo Chavez broker the recent release of six rebel hostages.

Five other prominent Colombians who have been in contact with the leftist Revolutionary Armed Forces of Colombia, or FARC, also are under investigation, Iguaran said.

He said the probes were prompted by documents found on laptops that Colombian authorities recovered during a March 1 cross-border raid on a rebel camp in Ecuador that killed FARC foreign minister Raul Reyes.

President Alvaro Uribe's government says the documents indicate Chavez was seeking to finance and arm the FARC while Ecuador's president, Rafael Correa, was seeking close ties. Both neighboring presidents deny the accusations.

The foreigners placed under investigation Thursday include two Ecuadoreans, a Venezuelan and the American consultant, James C. Jones, who has been working with Democrats in the U.S. Congress.

Jones told The Associated Press on Thursday that he considers the investigation of him "ludicrous."

He said his contacts with Reyes were purely mediation efforts, including trying to obtain the release of three U.S. military contractors held by the FARC since February 2003.

"I look at this and I laugh," Jones said in a telephone interview from the United States.

The Colombians being investigated include a journalist, a former deputy peace commissioner, the editor of the Colombian communist party's weekly newspaper and Alvaro Leyva, a former presidential candidate and longtime go-between with the rebels.

The five have never tried to conceal their contacts with the FARC.