Bogota - Prosecutors arrested a former army battalion commander Tuesday on charges of criminal conspiracy for allegedly colluding with right-wing death squads. Col. Hernán Mejía, former commander of the Popa Battalion, surrendered and denied the charges.

The chief prosecutor's office also ordered the arrest of three men formerly under Mejia's command -- Lt. Col. José Ruíz, Sgt. Aureliano Quejada and retired Sgt. Efraín Andrade.

The three were also charged with criminal conspiracy, and all but Quejada were apprehended, the office said in a communique.

Mejía, who commanded the battalion for two years beginning in January 2002, has been accused of inflating the number of rebels his troops killed by passing off paramilitaries' victims as rebels slain in army combat.

The chief prosecutor's office said at least 20 murder victims were presented as guerrillas slain in combat in 2002.

Former soldiers and paramilitaries who operated when Mejía ran the battalion have told The Associated Press that paramilitary militias regularly gave his troops the bodies of victims dressed in fatigues and presented as guerrillas.

In one case in October 2002, prosecutors say Mejía allegedly presented 18 men as slain rebels. Witnesses say they were paramilitary fighters killed by their own men.

''Everyone knew that this was an execution'' ordered by a paramilitary lieutenant named David Hernández, former army Sgt. Edwin Guzman told the AP in April 2007. Hernandez called Mejia to collect the bodies, Guzmán said.

Hernández was later killed in an army ambush, and Guzmán now lives in exile in the United States.

Colombian paramilitaries were formed in the 1980s to counter the country's leftist guerrillas. They killed thousands and stole millions of acres (hectares) of land beginning in the 1990s, seizing control of most of the Caribbean coast, prosecutors say.