Philippine president-elect Rodrigo Duterte may release jailed communist rebels in an effort to restart peace talks aimed at ending a decades-old insurgency that has claimed tens of thousands of lives, an aide said Tuesday.

The aide said Duterte, set to be sworn into office on June 30 after a landslide election victory on Monday, signalled his readiness to discuss the release of a number of imprisoned rebels, a key factor in the breakdown of peace negotiations three years ago.

Incumbent leader Benigno Aquino ended talks with the Communist Party of the Philippines in 2013 over the rebels' demand for the unconditional release of their detained comrades that his government was unwilling to grant.

Duterte spokesman Peter Lavina said the president-elect would consider allowing exiled communist leaders to return for the talks, and review the status of "political prisoners".

Lavina suggested the new government would not be averse to releasing detained rebels so they could take part in the talks, and allow ailing ones get treatment outside of prison.

"It is important to release political prisoners suffering from ailments," Lavina said.

Duterte, a hardline mayor accused of running vigilante death squads that have killed more than a thousand crime suspects in Davao, is a friend of Netherlands-based Jose Maria Sison, who set up the communist party in 1968.

Last month during the election campaign Duterte won the release of five Davao policemen and a civilian taken hostage by the rebels' New People's Army guerrillas a week earlier.

At the start of the campaign in February, Sison said in a video interview with the Philippine Daily Inquirer newspaper that the rebels were pleased all the would-be Aquino successors backed peace talks.

Sison claimed Duterte, his student in a political science subject at a Manila university in the 1960s, would consider a "coalition" as long as the communists disarmed.

Running for almost half a century, the communist insurgency has claimed 30,000 lives, according to military estimates.

The rebels' strength has dwindled to less than 4,000 fighters from a peak of more than 26,000 in the late 1980s, according to the military.