Facebook has been accused of “discriminatory and racist” behaviour after it deleted historical photos from a group that publishes archival photos of men and women from Papua New Guinea.

The group, which boasts over 55,000 members, claims photos showing traditional dress or ceremonies were deleted for allegedly containing nudity – but photos showing nudity among white people were not.

They are now calling on the social media giant to reconsider how it applies its community standards.

The group encourages users to post any historical photos with whatever background information that can be provided, with many publishing detailed breakdowns of photos from a wide range of contexts.

But users have been complaining of feeling censored, accusing Facebook of deleting some of the photos and banning some users from posting.

One of the group’s administrators, Arthur Smedley, told the Guardian he found Facebook’s application of its policy “ridiculous” after a fellow administrator, Peter Tate, was allegedly banned for posting a photo of a group of men “bare-chested with no covering to the upper part of their bodies”.

“As far as I’m concerned, it would mean for us in Australia that we’d be banned from posting images of men going to the beach during summer,” Smedley said. “Some users have said they’ve found these bans to be discriminatory and racist, that they take this stand against traditional, cultural activities.”

Smedley understood when others in the group claimed the censorship was racist.

“You could see it as racist, that an American company is discriminating against this group of people, saying these photos are banned from our group. The attitude is just incredible.”

A spokesperson for Facebook said that images had been removed in “error” and were being restored.

“Photos from this group were removed in error by an automated system but they have now been restored. We apologise for this mistake.”

Peter Kranz, a former executive director of information resources at the University of Papua New Guinea, said the heavy-handed approach was surprising.

“I’ve been blocked on three occasions for posting photos that are legitimate from historical documents, and are found in museums, libraries and collections around the world,” he said.

“It makes me very sad and disappointed, that we seem to be banning material that is of genuine academic and historical interest.

“In fact a lot of the material you could find at the Australian national archives, or the British Museum or the University of California. It is very disappointing that documents in the public domain, and of value historically, are being blocked by Facebook for what seems to be trivial reasons.”

Kranz said he was banned for posting photos of traditional courtship ceremonies, as well as photos from expeditions and from a funeral, and was told they were being deleted for nudity.

“I thought to myself, ‘Why are they blocking these photos, which have a lot of historical validity, yet allow people to post trivial stuff elsewhere?’

“It just suggests a bit of racism. They don’t seem to be applying their standards consistently.”

Kranz estimates that up to a dozen other users have been banned from posting in the group.

Kranz, who lived in PNG for five years and who has access to a wealth of historical material via his previous role at the University of Papua New Guinea, said the group had come to serve an important communal purpose.

“A lot of people find it very encouraging to find pictures and stories about the history of their country, and it is educating a lot of young people about the past,” he said.

The group had become a space for people to connect with their past and their ancestors, Kranz said.

“It’s very heartening when I come across a photo that is in living memory and someone will say ‘Hey, that’s my great-grandmother, I remember her, I saw her in the village in the ‘80s!’

“It can get very personal sometimes when people recognise their ancestors and relatives from the photos.”

Facebook’s community standards are applied by a combination of algorithm-driven AI, reports from users and reviews by their teams.

They can make exceptions in the application of the standards if the content is “newsworthy, significant, or important to the public interest”.

Facebook was accused in April of not doing enough to remove hate speech and racism on its platform.

The Australian Muslim Advocacy Network has lodged a complaint with the Australian Human Rights Commission over what the group alleges is Facebook’s failure to prevent the spread of hate speech.