A widening scandal in which three federal lawmakers have been jailed for allegedly organizing and benefiting from murderous right-wing militias is now implicating one of President Alvaro Uribe's closest political allies.

Sen. Alvaro Araujo, brother of Uribe's foreign minister, acknowledged in a radio interview Friday that he attended a 2004 party at which one of the country's most feared paramilitary leaders was present.

Araujo denied that his "marginal contact" with Rodrigo Tovar Pupo, better known as Jorge 40, implied he had any political dealings with the paramilitary commander, who is wanted in the United States for being among Colombia's biggest drug traffickers.

Uribe sought Friday to defuse what many Colombians think could become more damaging than the scandal involving drug cartel-financing of politicians in the mid-1990s that nearly toppled then-President Ernesto Samper.

He said any member of Congress found to be conspiring with illegal armed groups should be jailed and "punished with extra severity."

Uribe called upon "all congressmen to tell the country the truth and reveal whatever contacts they had with the paramilitaries."

Evidence is mounting that politicians across Colombia's Caribbean coast funneled public funds to the paramilitaries in exchange for election wins aided by paramilitary intimidation.

Despite having disarmed as part of a 2004 peace deal, paramilitaries are still believed to hold sway over huge parts of the country after killing hundreds and forcibly displacing tens of thousand of mostly poor Colombians in a nearly decade-long reign of terror.

Evidence of a long-running paramilitary-political mafia appeared to be confirmed last week when the Supreme Court ordered the arrest of four former and current members of Congress.

All four are all solid supporters of Uribe from the Caribbean state of Sucre and have either been arrested or turned themselves in. Sen. Jairo Merlano surrendered to police in Zipaquira, a town just north of Bogota, on Friday evening. A US$30,000 (€23,500) reward had been issued for information leading to his capture.

Araujo, whose powerful political family hails from the Caribbean state of Cesar, said he had spoken with Tovar on at least two occasions since 2002, including at the birthday party for an ex-congresswoman long suspected of paramilitary ties. But he denied any improper dealings.

"I've never made any political agreement with the paramilitaries," said Araujo, who vowed to cooperate fully with the Supreme Court investigation.

Although no charges have been filed against Araujo, opposition politicians have long tried to dig up evidence linking his fledgling Alas Equipo Colombia movement to the paramilitary groups.

In the epicenter of the scandal, Sucre, more than 2,000 friends and relatives buried on Friday lawyer Carmelo Berrios who had denounced fraud in local elections. He was shot Wednesday night by unknown gunmen in his hometown of Betulia.

Leaving the cemetery with weeping relatives, Rep. Jesus Berrios, the lone state assemblyman from the opposition Democratic Pole party, said his brother's murder shows how a dark alliance of paramilitary fighters and politicians continues to rule by terror across Colombia.

Many Sucrenos believe members of the political-paramilitary mafia running the state for the last decade killed 50-year-old Berrios to try to silence a public finally beginning to shed its fear of denouncing the state's discredited political class.

"And this mafia power quiets the voices of those who are against it," said Jesus Berrios, who was assigned a police bodyguard after his brother's killing. "Here in Colombia to think differently means a death penalty."

Uribe's administration has been conducting a peace process with the far-right paramilitaries that has seen more than 30,000 fighters disarm. Most of the leaders, including Tovar, are now in a specially created jail awaiting trial in which they face a maximum of eight years in prison for their role in some of the country's worst civilian massacres.

The paramilitaries surged in the 1980s as landowners created private armies to fight leftist rebels and extend their control across much of Colombia's countryside, but they quickly became corrupted by the nation's lucrative cocaine trade.

The U.S. government lists the paramilitaries as a "foreign terrorist organization" and is trying to extradite several of its leaders on drug trafficking charges.