New York City Mayor Michael Bloomberg is announcing his team’s latest investigation into illegal online firearms sales.

Bloomberg is the co-chair of the group Mayors Against Illegal Guns.

The group’s investigators spent eight weeks earlier this year monitoring gun sales on the website Armslist.com. The online classified marketplace is akin to a Craigslist for guns.

The investigation found that nearly one-third of guns are sold by high-volume sellers who do not possess the required license.

Bloomberg says the Internet is “flooded with guns.”

A representative from ArmsList.com did not immediately return a request for comment.

Bloomberg is leaving office at month’s end. He has vowed to continue to fund and stay involved with the pro-gun control organization.

(AP)