Speaking in Bogota on Thursday, Iguaran said: "After an analysis and a police report, there are indications of presumed ties between the Farc and three Colombian lawmakers, five Colombian citizens and four foreigners."
Colombian officials claim that Figueroa, a member of the Latin American parliament, was a Farc operative, but he responded to the allegations by telling state television on Friday that he "acted with complete legality".
In an interview on Thursday night with Venezuela's state radio, Figueroa had called the investigation a "big lie" and a "sham that aims to distract public attention".
Colombian officials said that one document found on the laptops obtained in the cross-border raid, which killed Raul Reyes, a Farc commander, and 24 others, showed that Figueroa visited a Chinese surface-to-air-missile factory and later delivered a catalogue to Farc.
|Cordoba had tried to broker a deal |
to free hostages held by Farc
Figueroa is also suspected of being involved in forming Venezuelan militia groups, a senior Colombian official said.
The other Colombians listed by prosecutors in the investigation include:
Piedad Cordoba, a senator who openly sympathised with Chavez's leftist ideas and tried to broker a deal to free hostages held by Farc, including Ingrid Betancourt, the French-Colombian politician
Alvaro Leyva, a former presidential candidate who has openly acted as a mediator between the government and Farc in the past and worked for a hostage accord.
Carlos Lozano, editor of the Communist party-linked newspaper, Voz, who told Caracol television after prosecutors listed him in the probe: "All we have done is work for peace and the humanitarian accord."
Colombian officials said the Farc documents further indicate that Maria Augusta Calle, a journalist and member of the assembly rewriting the Ecuadorean constitution, may have received financial support from the separatist group, .
Responding to the allegation, Calle said: "If it's a crime to have interviewed and gotten to know people from Farc, let them accuse me - but in Ecuador."
Among the others named in the Colombian investigation are a US academic and Ivan Larrea, a former Ecuadorean presidential candidate.
For his part, Larrea called the probe "a witch hunt" in a phone interview with Ecuavisa television.
His brother Gustavo, who is Ecuador's internal security minister, has acknowledged meeting Reyes, maintaining that it was part of efforts to secure the release of Farc hostages.
Larrea suggested that the accusation was a ploy by the government of Alvaro Uribe, the Colombian president, to distract attention from its "internal political crisis".
More than 30 members of Colombia's congress, mostly allies of Uribe, are in jail on charges of colluding with paramilitary militias.
Three politicians have been arrested on bribery charges in connection with a congressional vote that enabled Uribe's 2006 re-election.
Uribe's government says the documents seized in the March raid indicate that Hugo Chavez, the Venezuelan president, was seeking to finance and arm the Farc while Rafael Correa, Ecuador's president, was seeking close ties with it.
Both Chavez and Correa deny the charges.