The latest in a long tradition of Internet and e-mail scams to hit the United States from Nigeria is the targeting of vacation rental firms.”Every other Nigerian scam out there is getting more and more sophisticated,” police Inspector Brian Brunault of NEWBURYPORT said.

Vacation Home Rentals received a call earlier this month from a man in Maryland saying his property was listed as being a rental. The only problem was, along with the description of his home and photographs, a different name and mailing address for payment was attached.

“What worked for them in the past doesn’t anymore so they devise more and more scams,” he said. Carol Irvine and Jerry Jongerius of Idyllrentals.com said they contacted Thomas Gilmore of Vacation Home Rentals after they found out about the scam.

“The only problem, he never rented from us,” said Jongerius, who lives in Maryland. “To make a very long story short, someone posted our rental properties on the Web, posing as the owner, and collected rental deposits for next year. We know of one such renter, Tim, who sent a registered check for $4,550 to the fraudulent address in Wisconsin.”

“Since then, we found our property on other sites as well, such as Vacation Rentals,” Jongerius said. “We have been contacting everyone trying to get the listing taken down.”

Gilmore said he takes steps to protect himself by cross-checking information and trying to block IP addresses from fraudulent sites. He says since starting Vacation Rentals five years ago, he has run into scams about three times.

“We have 1,200 properties and $100 million in rental transactions,” Gilmore said. “Any online business runs into these problems.

“They are doing all they can,” Brunault said. “The Nigerians put a lot of thought into their scams, and you don’t even know they are scams anymore. You have to stay on top of it, and if it sounds too good to be true, it probably is.”