The Colombian attorney general says he is investigating 22 generals for their alleged roles in the murder of civilians in the “false positives” scandal.
It involves the murder of civilians whose bodies were then passed off as those of Farc rebels or paramilitaries to boost combat kill rates.
Eight hundred members of the security forces have been jailed so far.
Mr Montealegre said he would deliver the results by the end of the year.
He told the first conference in Colombia for victims of extra-judicial killings that some of the generals were still on active service and others had retired.
He said more than 5,000 members of the security forces had been implicated.
The “false positive” scandal erupted in 2008 when it was found that a group of poor young men had been recruited from the slums of Bogota, promised well-paying jobs in the province of Norte de Santander, then murdered in cold blood and their bodies presented in rebel uniforms as having been killed in combat.
From then on many other cases of “false positives” came to light across the country and prosecutors now have thousands of cases on their books.
In some areas of the country, there were cases of soldiers being sent to round up homeless people.
Members of the army, police and navy used their boosted success rates to claim promotion and perks such as days off.
Correspondents say Colombia’s willingness to bring to justice members of the armed forces involved in the forced disappearances of innocent civilians will be watched closely in Havana by the Farc who are in peace talks with the government.
The Farc have said the state’s willingness to investigate and prosecute crimes committed by its own agents will be central to the reconciliation process.