Senga said military agents captured Delfin de Guzman, alias Rafael Cruz, 38, in his house at Barangay San Mateo in Norzagaray, Bulacan last May 11 on the strength of a court-issued warrant.
When cornered, De Guzman, did not resist arrest, the Intelligence Service of the Armed Forces of the Philippines (ISAFP) reported.
Senga said De Guzman had confessed in an affidavit to taking part in the killing of Kintanar and Tabara.
"He (De Guzman) confessed that he was behind these assassinations," Senga said.
Senga refused to link De Guzman’s arrest to government claims that his comrades were behind the murders of leftist activists.
"This is outside of the issue," he said. "If we gather information, we will act accordingly."
De Guzman is secretary of the Bulacan Provincial Party Committee and acting regional secretary of the Central Luzon Regional Party Committee of the Communist Party of the Philippines, he added.
The military also linked De Guzman to a number of killings of soldiers and policemen in Central Luzon and attacks on telecommunications towers in the region and extortion activities in Bulacan.
Maj. Gen. Jose Angel Honrado, Armed Forces spokesman, said De Guzman’s involvement in the murder of former comrades only showed that the (CPP) was involved in the killings.
"This is a clear evidence that members of the party are involved in the killings of their peers," he said.
Kintanar was gunned down in a Japanese restaurant in Quezon City in January 2003. Tabara was shot dead at the parking lot of a shopping mall in Fairview, also in Quezon City in late 2004.
An ISAFP report said De Guzman shot Tabara and acted as backup for the killer of Kintanar.
Kintanar and Tabara, along with Felimon Lagman, who was shot dead on the University of the Philippines campus in Quezon City, broke away from the CPP in the 1990s.
The three later formed the Rebolusyonaryong Proletariat Army-Alex Boncayao Brigade, a hit squad behind the series of killings of "perceived enemies of the people" in urban centers. — With Perseus Echeminada