Peru's military said Tuesday that the second-in-command of the Shining Path guerrilla movement had died in January following a military strike on a rebel camp.
Jorge Quispe Palomino, known as Comrade Raul, died on January 27 "as a result of a chronic kidney disease" that was aggravated by an armed forces attack on a rebel camp in October, the military's joint command said in a statement.
His death was the result of injuries sustained from "helicopter fire over a terrorist camp," it added.
"This information was hidden from his own troops to avoid demoralization and other negative effects within the terrorist organization," said the statement.
Quispe Palomino was one of the most wanted people in Peru and the brother of the Shining Path leader Victor Quispe Palomino, known as Comrade Jose.
Most of the Shining Path's top leaders have been detained but Comrade Jose remains at large with the remnants of the militant group which are active in the major coca-growing area of Peru, collaborating with drug-traffickers.
Peru's government had placed a bounty of two million soles ($550,000) on Comrade Raul's head.
The Shining Path, an offshoot of various communist political parties, launched its "popular war" in May 1980 and was known for its brutality.
Two decades of conflicts with armed forces left 69,000 people either dead or missing, according to the country's truth and reconciliation commission.
Although the group was never fully defeated, it is now believed to consist of just 350 members, including 80 armed militants commanded by the Quispe Palomino brothers.
Peru is one of the world's largest producers of cocaine and its major ingredient, the coca leaf.