Amnesty International renewed calls for an end to sorcery-related violence in Papua New Guinea on Friday following a report that six women were tortured with hot irons in an Easter "sacrifice."

Amnesty said Papua New Guinea police were investigating the incident, but police in Port Moresby were unable to confirm this to AFP.

It comes just weeks after a woman accused of sorcery was burned to death by a mob.

A report in The National newspaper said that six women and a man accused of sorcery were tortured as Easter "sacrifices" in a village in the Southern Highlands on March 28.

The man, Komape Lap, 54, told the newspaper he fought with his attackers and escaped but did not know what had become of the six women, two of whom were his wives.

He said the women had their hands tied, were stripped naked and had hot irons placed "into their genitals" during the ordeal.

Amnesty called on authorities in PNG to prevent and punish such violence.

"The priority must be to find out the fate of the six women," Amnesty International's Pacific researcher Kate Schuetze said.

"The perpetrators must also be brought to justice for the abduction and crimes of sexual and other violence, if confirmed."

The claim follows the death of a young mother in February who was stripped naked, doused with petrol and set alight on a main street in the Western Highlands town of Mount Hagen as hundreds of people watched.

The woman, aged 20, had been accused of causing the death of a young boy and the case attracted global attention after images of her body burning on a pile of rubbish were published.

Schuetze said while the latest incident in the impoverished country, where communications are difficult, had not been confirmed, it was important that authorities investigated the claim regardless.

"This type of violence is carried out in the Highlands and it is reported regularly," she said.

Schuetze urged the government to stamp out the practice in the Pacific nation where there is a widespread belief in sorcery and where many people do not accept natural causes as an explanation for misfortune and death.

"The government must take urgent action to prevent any further 'sorcery'-related violence and must also provide the survivors with support and full access to health and other services," she said.

There have been several other cases of witchcraft and cannibalism in PNG in recent years, with a man reportedly found eating his screaming, newborn son during a sorcery initiation ceremony in 2011.