The U.S. Attorney's Office has intervened to prevent former Lighthouse Inn operator Christopher Plummer from selling more than four acres of waterfront land he owns in Stonington, saying the property, valued at $800,000, is tied to a fraudulent financial transaction.

The civil complaint, filed last week in U.S. District Court by U.S. Attorney David B. Fein and Assistant U.S. Attorney Julie G. Turbert, states that Plummer bilked money out of an unnamed investor to make mortgage payments on the Stonington property. The suit said Plummer had been engaged in mail or wire fraud or a conspiracy to commit unlawful acts, although the U.S. Attorney's Office said it has not charged Plummer with a crime.

U.S. Attorney's Office spokesman Tom Carson refused further comment, but the civil action lays out the federal case against Plummer.

"Plummer engaged in a scheme to defraud and to obtain money and property from an investor ... by means of materially false and fraudulent pretenses, representations and promises," according to the suit.

Authorities will seek forfeiture of the undeveloped 4.35 acres on Palmer Neck Road by starting foreclosure proceedings on the property, the suit said. But the property may have claims against it filed by the Town of Stonington, according to the suit, which added that Advantage Mortgage Co. Inc. may also be owed hundreds of thousands of dollars for various loans.

The land previously had gone into foreclosure, according to court documents, but was rescued when Plummer "utilized $40,000 of the victim's money to make mortgage payments."

According to the suit, Plummer promised the investor that he had access to a computer-based trading system that would double the person's money in two years. In May 2008, the investor gave $200,000 to Plummer, who later said the money was being held with Interactive Brokers in Greenwich, though the account didn't exist, the suit said.

"Plummer diverted this money to his own use through a variety of large and small purchases and payments," the suit added.

Plummer deposited the investor's $200,000 into a Liberty Bank account he controlled in the name of Madison and Wall LLC, the suit said. The document said Plummer wrote checks from this account, payable to himself, totaling $116,550. Other checks went to the state Department of Revenue Services, The Home Depot, U.S. Airways, Priceline.com and a woman named Margaret Coles with whom he once shared an address in Lyme and recently was involved with in a custody battle.

The investor, who according to the suit cooperated this year with an FBI investigation of Plummer, has seen only $20,000 of his money returned, documents indicate.

Plummer was the day-to-day operator of the Lighthouse Inn two years ago when health inspectors closed down its restaurant and bar for code violations. He left a mountain of unpaid bills behind at the inn, which closed entirely in early 2009, and workers claimed he had not paid them wages.

Plummer later filed an involuntary bankruptcy petition that delayed the landmark mansion's auction. A New Haven businessman purchased the historic inn at auction but then backed out, prompting a Superior Court judge last month to turn over ownership to the mortgage holder.

Last year Plummer and fellow former Lighthouse Inn principal Maureen Clark were accused of defrauding Indianapolis resident Peter J. Molina and his ex-wife, Teresa A. Barnes, of $100,000 each. Clark and Plummer, former Lighthouse Inn ownership group McGrath Hotels LLC, the Lighthouse Group of Connecticut LLC and the Lighthouse Inn and Resort were barred from selling securities in Indiana, according to documents obtained by The Day.

In 2004 Plummer was sentenced to six months of home confinement for failure to pay federal taxes, according to the Internal Revenue Service.