Sold to the highest bidder. Not anymore. The sale of skulls on eBay has been banned.

Hundreds of mystery skulls were sold for US$5500 (NZ$7700) on US auction site eBay, prompting the site to ban the sale of all human remains.

The site had previously allowed the sale of "items containing human scalp hair, and skulls and skeletons intended for medical use", New Scientist reports.

Policy on eBay's website stated that all other human remains was banned. However, sellers could say skulls were for medical use without proving it, and still sell them as curiosities, says Tanya Marsh at Wake Forest University in Winston Salem, North Carolina.

The updated police now bans the sale of skulls and skeletons, along with all other body parts, and clearly states: "You can't sell any of these items even if you state they are intended for medical research."

A study by the Louisiana Department of Justice in Baton Rouge tracked skull sales on eBay for seven months, and found that 237 sellers listed 454 skulls on the site, with bids reaching US$5500.

READ MORE:

* New Zealand's biggest and most bizarre auctions

* Brexit number plate sold on Trade Me

* Trade Me's creepiest auctions

"We should have a strong moral problem with that," Wake told New Scientist.

"You can't tell just by looking at them.

"It's possible that some of them are disinterred human remains," she said.

The study, They Sell Skulls Online, was published in the Journal of Forensic Sciences and suggested skeletons that have appeared on eBay were mostly donated to medical science, but many may have been discovered on archaeological digs.

"Ultimately, the goal is to stem the commodification of such items and to recover skeletal material, especially that which may be of archaeological or forensic significance, and provide the proper final disposition for such material," the study stated.

US law prohibits the sale of Native American remains, but there are no other federal regulations on the trade of human skulls online. It is left to individual states to impose such regulations and, according to the Louisiana Department of Justice researchers, 38 states do have laws prohibiting the sale of human remains.

In New Zealand, Trade Me bans the sale of human and animal remains, including ashes.