"The couple Benito and Wilma Tiamzon finally walked free," Xinhua news agency quoted Edre Olalia, peace panel legal consultant of the National Democratic Front (NDF) as saying.
"They will join 14 others released for peace talks in Oslo and for consultations with NDF Negotiating Panel," Olalia said in a Facebook post.
The participation of the Tiamzons in the peace talks "ensures an inclusive outcome, hopefully to end conflict and bring about comprehensive and sustainable peace throughout the land", Presidential Adviser on the Peace Process Jesus Dureza, who will lead the government delegation in the formal peace talks in Oslo starting August 22, said.
The Tiamzon couple were arrested in Cebu province in March 2014 on multiple murder charges.
Benito is the chairman of the Communist Party of the Philippines-New People's Army (CPP-NPA), while his wife Wilma is the secretary general.
The CPP-NPA-NDF is waging Asia's longest running insurgency since the 1960s.
The formal peace talks between the government and the leftist rebel group bogged down in 2011 during the administration of then President Benigno Simeon "Noynoy" Cojuangco Aquino III.
