Philippines president-elect Rodrigo Duterte says he will allow the body of dictator Ferdinand Marcos to be buried at a heroes' cemetery.

Mr Duterte also said he would pardon ex-president Gloria Arroyo, who is being detained at a military hospital while on trial for graft and vote fraud.

The announcements by Mr Duterte, who takes office on June 30, are sure to enrage critics who warned ahead of his landslide election on May 9 that he was a dictator in the making with no regard for the rule of law.

Speaking in his hometown of Davao, he said he was prepared to risk nationwide unrest on the flashpoint issues surrounding two of the nation's most controversial figures.

"I will allow protests," Mr Duterte said, when asked about the expected reaction.

Former Philippine president Gloria Arroyo leaves an anti-graft court in Quezon City in 2012. ( Reuters: Cheryl Ravelo )

Mr Duterte said he would grant the longstanding wish of the Marcos family to have the patriarch buried at a Manila cemetery for some of the nation's most revered war heroes.

"I will allow the burial of Marcos in the Heroes' Cemetery, not because he was a hero but because he was a Filipino soldier," Mr Duterte said.

He also said that he believed Arroyo, who has been detained since 2011, should be free.

"I'm ready to grant a pardon to Arroyo. Arroyo to my mind should already be released," he said of the president that served from 2001 to 2010.

Ferdinand Marcos Jr likely to narrowly lose vice-presidency

Marcos and his family fled to US exile in 1986 after millions took to the streets in a famous "People Power" revolution.

At the time he was accused of overseeing massive widespread human rights abuses and plundering $13.9 billion from state coffers, dying three years later in Hawaii.

His embalmed body is now stored in a crypt at the family home in the northern Philippines.

His son and namesake, Ferdinand Marcos Jr, has led a remarkable political comeback for the family, rising to become a senator in 2010 and running for the vice-presidency in the latest elections.

Mr Marcos Jnr is currently in second place in the tally count and is likely to lose narrowly to Leni Robredo.

However, at 58, he is still young enough to one day achieve his goal of becoming president.

The Marcos clan has insisted the late ruler deserves to be buried at the cemetery, arguing he was a World War Two hero for resisting the Japanese occupiers.

However, American and local historians have disputed his military credentials.

Mr Duterte said allowing Marcos to be buried at the cemetery did not necessarily make him a hero, pointing out other soldiers without gloried reputations were also there.

But current President Benigno Aquino, whose parents led the democracy movement against Marcos, did not allow the burial, arguing it would be the "height of injustice".

AFP