Sept. 21, 2012  -- The online marketplace eBay has said it will begin removing listings for beer and liquor from its site after a teen working with "20/20" successfully ordered vodka from two eBay vendors. The vendors advertised their products as "collectible."

While eBay prohibits the sale of all alcohol with the exception of some wines sold by licensed wine sellers, it does allow for the sale of collectible alcohol containers. The site's current alcohol policy states that the seller of the container "will take all appropriate steps to ensure that the buyer is of lawful age in the buyer's and seller's jurisdiction."

But that didn't stop one teen who worked with "20/20" from obtaining alcohol through the site. We asked Xander, 13, to head to the site and try to buy liquor there. One vendor refused to sell his product when Xander and a "20/20" producer declined to send a copy of an ID showing that the buyer was of legal drinking age. But Xander was able to successfully place an order with two other vendors -- a result that mirrored work done by researchers at the University of North Carolina, who found during a recent study that teens could order alcohol from a number of sites, including eBay.

READ: 5 Shocking Ways Your Kids Try to Get Drunk

"All I had to do was type in vodka on the search bar, click one button and it can send it to my house," Xander told "20/20." (A "20/20" producer paid for the purchases.)

Weeks later, five bottles of vodka arrived at Xander's front door.

In a statement to "20/20" this morning, following the posting of an ABCNews.com article about Xander's experience, eBay said it is completely revising its alcohol sales practices to protect against illegal sales:

"eBay will not allow our marketplace to be used as a way to circumvent laws regarding the sale of alcohol, particularly the illegal sale of alcohol to minors. We are beginning the process of removing listings of beer and spirits. We expect to allow these listings again after developing and implementing additional, reasonable requirements to support seller compliance with our policies and applicable laws. We will continue to allow listings by pre-approved, licensed wine sellers."

The company said earlier that it had taken action against the two vendors who sold alcohol to Xander.

Researchers at the University of North Carolina at Chapel Hill have found that many Internet alcohol vendors fail to verify that customers are of legal drinking age. In a report on a study released in May, researchers said that underage study participants successfully ordered alcohol online 45 times from popular vendors, including eBay.

"With just a few clicks on their computer or smartphone, kids can order alcohol delivered to their home," lead study author Rebecca Williams, a research associate at UNC, said after the study's release. "We were amazed at how easy it was for minors to buy alcohol online."

Williams said that researchers found listings on eBay that were not in line with the site's own criteria for what constitutes an alcohol-related collectible.

According to the site's current policy, the contents of the collectible must not be intended for consumption, that the value of the item is in its container, not its contents, and that the item must not be available in any retail outlet.

"Our simple searches revealed countless unrestricted listings by the sellers of common liquors that clearly didn't meet any of the criteria, such as varieties of Bacardi rum available at any liquor store," Williams said.

What remains unclear, Williams said, is how often teens today are actually using eBay and other online retailers to purchase alcohol. A 2006 study sponsored by the wine industry found that just 2 percent of teens reported buying alcohol online. Williams said she hopes to do her own study on the subject, through a nationally representative survey, next year.

Watch the full story on the latest episode of "20/20" online here.