A Hungarian scam artist who operated out of a Dupont Circle hotel pleaded guilty to a scheme that advertised the sale of boats and cars online, but never came through with the delivery of the vehicles, authorities said.

Istvan Laszlo Csurgo, 31, was part of a three-person international crew that in three months last summer swindled more than $1 million from victims from around the United States, according to charging documents.