Teenagers can purchase alcohol on eBay, according to an investigation by the news show "20/20."

The website prohibits the sale of all alcohol, except for some wines, but allows the sale of collectible alcohol containers, according to ABC News.

The site's alcohol policy states sellers of the containers "will take all appropriate steps to ensure that the buyer is of lawful age in the buyer's and seller's jurisdiction."

The news show asked a 13-year-old to try to buy liquor on the website. He was able to place orders with two vendors.

A third refused to sell his product without seeing a copy of an ID showing the buyer was of legal drinking age. After learning about the sales, eBay said it has taken action against the two vendors who sold the alcohol.

A study published in May found minors are often able to buy alcohol online, because many Internet alcohol sellers and shipping companies do not verify the buyer's age. Researchers at the University of North Carolina at Chapel Hill recruited eight participants, ages 18 to 20, to try to buy wine, beer and other alcoholic beverages online. They were told to lie about their age when filling out order forms. If they were asked to verify their age by a delivery person, they were instructed to say they were not yet 21.

Participants placed orders at 100 Internet websites, and most deliveries were made by FedEx or United Parcel Service. Of those orders, 45 were successfully made and received. Just 28 orders were rejected because the person placing the order was found to be a minor. The rest of the orders did not go through because there were technical difficulties, or because no one was home at the time of attempted delivery.

The researcher of that study, Rebecca Williams, told ABC News that it is unclear how many teens are using online retailers such as eBay to buy alcohol.

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