A Minnesota man bought more than 60 AK-47-style rifles at retail prices and sold then online for a profit without a license, according to federal agents.

The Pioneer Press reports the man sold some 25 rifles for about $250 more than the retail price he paid. Agents seized 60 rifles from the man's home. He said he was selling the guns to pay for cancer treatments for his dog.

Officials say employees at Mills Fleet Farm first alerted authorities about the man making multiple purchases of Romarm/Cugir AES 10B guns, a Romanian semiautomatic weapon. They say he then sold them through the website Gunbroker.com. It's not illegal for a person to sell a gun to another individual, but sellers need a license if they repeatedly sell arms at a profit.

The man is not charged with a crime, but federal authorities filed suit seeking forfeiture of the 60 guns they seized from his homes.

The case surfaced just as the Senate was voting on whether to expand background checks on gun buyers, which would hinder sales of weapons by individuals and gun show vendors. Minnesota's two DFL senators expressed disappointment the measure failed to pass, MPR reported.