Even Colombians accustomed to treachery and deceit after more than a half-century of civil conflict and drug violence were stunned by the arrest of a one-time provincial lawmaker for allegedly helping plan the mass kidnapping of 11 colleagues later slain by leftist rebels.

Even more remarkable, the alleged traitor was among the kidnapped, and "miraculously" survived seven years later when the others were killed in murky circumstances.

"I can't get it in my head that this could actually have been possible," Interior Minister Federico Renjifo said after last week's arrest of Sigifredo Lopez. "I can only hold out the hope, as a human being, that this doesn't turn out to be true."

Plenty of Colombians, including relatives of the slain deputies, are perplexed by the arrest of Lopez on suspicion of murder, hostage-taking, perfidy and rebellion in connection with events that began on April 11, 2002, when guerrillas of the Revolutionary Armed Forces of Colombia disguised as soldiers slipped into the state Assembly building in Cali, the Andean nation's No. 3 city, and rounded up the deputies, killing a police officer.

Prosecutors have not yet offered a possible motive for the ex-lawmaker's arrest, prompting speculation that the 49-year-old Lopez, released by the FARC in 2009, was somehow double-crossed by the rebels.

Did he truly endure a harsh jungle captivity? Could he be a rebel mole?

"Judas?" asks the cover of Colombia's top newsmagazine, Semana, wondering if Lopez can be likened to the biblical betrayer of Jesus Christ.

Prosecutors have based their case on a 40-minute video discovered in the digital data trove of Alfonso Cano, the FARC commander in chief slain by the military in November, said an official in the chief prosecutor's office who has seen it.

"In the video, a man is explaining to the guerrillas in detail the layout of the Valle (del Cauca) Legislature," said the official, who spoke on condition of anonymity because the case file is not yet public.

The man calls police posted at a nearby station "the enemy" but he does not mention an armed raid on the legislature. His face is not visible. Only his voice is heard as he runs down the location of entrances and exits in the building, the official added. Until, that is, he drops a piece of paper and the silhouette of his face shows.

Investigators spent months analyzing the silhouette and matching the voice print to confirm their suspicion it was Lopez, the official said.

Lopez, who last year ran unsuccessfully for congress and for Cali mayor, had called his survival in the confusing deaths of the other 11 deputies "a miracle of God."

He said the FARC had separated him from the others when their guerrilla jailers, mistaking an approaching rebel unit for a military patrol, shot and killed them all. Standing orders in the FARC mandate that rebels should prevent prisoners from being rescued alive.

Lopez said he was nearby and saw nothing but heard the bursts of gunfire, only learning of the slaughter two weeks later from his rebel guards.

"It's a story that generates much suspicion," said the official in the prosecutor's office familiar with the case.

That part of the story is given credence, though, by a message later found in a slain rebel commander's laptop in which Cano says "a deputy survived who was being held in another place ... who didn't see anything, only heard it," Semana reported.

Another reason to suspect Lopez: He served as mayor in the 1990s of his hometown of Pradera, long a FARC sanctuary. In a country with a weak central state, local authorities have always been pressured to get along with whichever armed group happens to control their area.

"Contacts between the civilian population and the rebels are constant," said security analyst Alfredo Rangel of the Seguridad y Democracia foundation.

The official in the chief prosecutor's office said without offering details that several FARC deserters have also implicated Lopez in the 2002 kidnapping.

In a court hearing last week, Lopez denied he was the man in the video and declared himself innocent. His lawyer, Alfredo Montenegro, suggested that foreign experts, such as the U.S. Federal Bureau of Investigation, compare the silhouette and voice print.

The prosecution has its doubters.

"If you apply logic to the case it's impossible that it could be true because no one is going to have themselves kidnapped so they can spent seven years (in captivity) and come out without teeth and not right in the head," said the Cali writer and radio commentator Gustavo Alvarez Gardeazabal.

The day of his release, Lopez's discourse was rambling and not always coherent when he met with reporters. He was the last of a series of politicians freed by the FARC, which announced three months ago that it was halting ransom kidnappings. It released 10 soldiers and police officers last month it described as its last "political prisoners."

The FARC holds a French journalist who was accompanying a military patrol attacked by insurgents on April 28 but has promised to free him soon.

The co-author of the book that Lopez published last year, Julio Cesar Londono, says the physical toll of Lopez's 82 months included the loss of teeth, severe gastritis, a hernia and heart trouble.

"He endures seven years in the jungle in the hands of that oldest, stupidest and cruelest rebels in the word, suffers all manner of ignominy, doesn't see his kids grow up," Londono wrote in a newspaper column. "His wife is the victim of con men peddling false hopes ... His mother suffers serious health setbacks due to the traumatic stress."

Lopez's wife, Patricia Nieto, has refused to discuss her husband's legal troubles. The couple has two sons, ages 21 and 23.

Relatives of slain deputies who spent considerable time with Nieto over the years were shocked by Lopez's arrest.

"I hope there has been some kind of confusion or some error," said Diego Quintero, who lost his brother, Alberto.

In the book about his ordeal titled "Sigifredo: The Triumph of Hope," Lopez says he had to acknowledge the "the masterful manner" in which the mass kidnapping was planned. And he laments the death of the police officer who had his throat cut during the rebel raid.

"Today, every time I see a soldier or a police officer, "I want to hug them and thank them for the good they do the country," he wrote.


Associated Press writer Frank Bajak contributed to this report.