THE future of one of Oxford's most popular artefacts - the shrunken heads at the Pitt Rivers Museum - could be in doubt.

The South American heads draw hundreds of visitors to the Victorian museum in South Parks Road - and are particularly popular with children.

Curator Laura Peers is undertaking an "informal" review, which could lead to the heads being removed from display and stored elsewhere in the museum, or repatriated, because she questions the ethics of holding the heads.

Last night, Philip Pullman, who featured the museum in the award-winning His Dark Materials trilogy, said: "I think the shrunken heads should stay".

Dr Peers, who has served on a government-run working group on human remains, said she felt "uncomfortable" about the shrunken heads on display.

She added: "I personally would like to know more what the communities in Ecuador and Peru feel about it.

"We have never had a formal review of any particular display - this is an awkward area where personal views and professional training become mixed."

Dr Peers added she was trying to analyse visitors' responses to the heads, including those of children, but was not ready to arrive at any conclusions.

Dr Michael O'Hanlon, the museum's director, said: "The whole issue of human remains is, and has been widely debated in museums across the country.

"There are a range of legitimate perspectives people can take on this and, this being a university museum, we debate them.

"There are no plans at present to remove the shrunken heads from display, but the display has been changed recently and we will continue to keep it under review."

Margaret Dyke, a spokesman for the Friends of the Pitt Rivers Museum, which raises funds, said: "I think the shrunken heads are the museum's number one exhibit.

"The children love them - they like being scared - and if they were removed the children would miss them."

Children's author Philip Pullman, who is a Friend of the museum, based one of the chapters of The Subtle Knife on a visit by Lyra, when she sees some ancient skulls on the first floor.

Mr Pullman said he wanted the shrunken heads to stay and added: "The value of the shrunken heads is that they are real - you could replace them with plastic models but that would not be the same.

"It would be very hard to find the living relatives - although you could extract some DNA.

"I can understand the complexity of feeling about this and we could be on the cusp of a cultural change regarding this kind of exhibit - in 100 years' time people may say how brutal we were.

"The great value of the Pitt Rivers Museum is the higgledy-piggledy nature of the displays, which itself is a window into the past, and the shrunken heads are part of that."

Dr Peers said museum staff had made changes to the shrunken heads case to ensure that the human remains were displayed in an educational and respectful manner.

She added: "We have updated the case text on the shrunken heads, focusing on their meanings within Shuar culture where they were made.

"We have added a new case text, inviting the viewer to think about how the bodies of dead enemies are treated by different societies around the world, and why."