Experts warn that human breast milk can contain harmfulbacteria, drugs and viruses, and that it can be sold online.

eBay said it had updated its automatic filters to stop breast milk from being sold on the site in the future.

Dr Sarah Steele, a public health researcher at the University of Cambridge, said that while human breast milk had been sold for some time on online platforms, it had usually been listed with some information about the potential risks.

She noticed a marked rise in the number of advertisements after reports on social media of women earning as much as 10,000 dollars for selling their milk to athletes.

We need to remember that it is a body fluid. The rise of listings on auction sites and online social marketplaces with buy-it-now prices, minimal information about the seller, and no reference to any safety advice or information is what I have observed recently.

The idea of remote sale from a total stranger you will never meet is a new idea. You don't know who is at the other end of the transaction. She said it was very unsafe.

Most of the shipping via Royal Mail is not temperature controlled. You don't send mate milk via Royal Mail when they run out. There are a number of food safety protocols that online grocery sites have to implement.

The advert on eBay was posted by a 36-year-old in the UK and charged 15 dollars for 150 grams of breast milk.

There is an oversupply of human breast milk for sale, and it will be posted frozen in insulated packaging.

The sale of human breast milk is not allowed on eBay. We have removed listings of this item and updated our automatic block filters to prevent it from being listed in the future.

Milk banks in the UK give free human breast milk to babies who need it. These carry out lifestyle checks on donors for factors such as smoking or drug use, and screening of donors to check for infections such as HIV, Hepatitis B and syphilis. Breast milk is pasteurised for safety.

CMV can be found in households with cats, Steele said. The virus can cause serious health problems in unborn babies and adults with weakened immune systems.

While people assume the buyers are parents of newborns, a lot of people looking for milk online are adults who are looking for an alternative therapy when they have cancer or other conditions because they believe it will either offer an immune boost or be a source of milk.

A lot of the promises people read about in online forums about the miracles of breast milk for adults don't hold up to science, and the risks of buying this online outweigh any purported benefits.

Steele said that research has shown that human breast milk from online sellers can be rich in gram-negativebacteria, which can be harmful.

Steele said that human breast milk sold online may be contaminated with cow's milk or other fluid, while the storage bags used may mean the milk could contain other substances.