Josef Meyers is accused of stealing this 18th Century Louis XV Ormolu-mounted commode from Barbara Rockefeller's Upper East Side mansion. View Full Caption Courtesy of Duane Morris LLP

UPPER EAST SIDE — The Rockefellers were snookered by a con man as slick as the oil that made them rich.

Josef Meyers, a convicted felon and former federal informant for FBI agent-turned-congressman Michael Grimm, wheedled his way into a close friendship with a dowager of the storied dynasty — then suckered her out of a cherished antique before she died, a new lawsuit charges.

The fraudster is accused of masquerading as an Austrian prince in 2003 to cozy up to Barbara “Bobo” Rockefeller, the elderly ex-wife of a former Arkansas governor and heir to the Standard Oil fortune.

Meyers’ insinuations worked so well on the then 87-year-old Rockefeller that she allowed him, his girlfriend and their children to shack up with her for eight months in her opulent six-story Upper East Side mansion, the lawsuit claims.

Josef Meyers, a former FBI informant, was arrested in 2010 for owing more than $220,000 in child support in Oakland County, Michigan. View Full Caption Oakland County Sheriffs Office

Part of the grift involved Meyers moving an 18th Century Louis XV Ormolu-mounted commode worth as much as $80,000 out of the house under the pretense that he was storing it for safekeeping, the lawsuit says. In reality, he is accused of selling it to a London art dealer.

The Rockefellers only figured out the alleged con in May 2011 — three years after Barbara’s death — when a family friend read a New Yorker article about Meyer’s criminal past, his bogus royal claims and his role as an informant for federal agents.

“According to the article, and various other news articles we read online, Josef had been arrested for failure to pay child support in 2010 and was subsequently convicted and imprisoned,” Barbara’s daughter-in-law, Lisenne Rockefeller, said in an affidavit accompanying the lawsuit.

“We also learned that Josef had at one point been committed to a psychiatric hospital and that he had a criminal history for charges such as assaulting his mother, drugs and weapons, cashing a bad check and dealing counterfeit goods.”

The Rockefellers also learned of the commode’s whereabouts in November 2011, when another friend spotted it up for auction in a Sotheby’s catalog.

As the executor of Barbara’s estate, Lisenne filed the lawsuit last week in Manhattan Surrogate’s Court, demanding that Clovis Whitfield — the art dealer who purchased the commode from Meyers and later put it up for auction — return it.

Meyers met Barbara Rockefeller in late 2003, when her granddaughter invited him to a holiday party at her $25 million East 67th Street home.

The scammer presented himself as Prince Josef von Habsburg-Lothringen of Austria, the lawsuit says.

In reality he was a married Michigan dad who had multiple run-ins with the law and had abandoned his family in 1993 to move to New York. Living in a SoHo apartment, Meyers reinvented himself as a worldly royal who boasted of turns as a financier, stockbroker and real estate developer, according to the New Yorker.

With this fake pedigree, Meyers also worked as an informant for the FBI, including on a 2002 case dubbed “Wooden Nickel” that helped then G-Man Michael Grimm take down allegedly crooked Wall Streeters.

Meyers’ phony aristocratic airs apparently made a fast impression on Barbara Rockefeller, a coal miner’s daughter who married and divorced Winthrop Aldrich Rockefeller.

Within a few months of knowing Barbara, Meyers, his girlfriend, Michelle Trico, and their children were sleeping over at her mansion, surprising her family and friends, the lawsuit says.

“I found this particularly odd given that Josef and his family said they had an apartment of their own downtown,” Barbara’s friend Salvatore Mule said in an affidavit.

Soon Meyers began advising Barbara about her household. He fired all but two of her staff, blocked many friends from seeing her and changed the locks to her home, the lawsuit says.

When Mule visited her in early 2005, he noticed that her beloved commode — which she owned for four decades and kept in her living room — had been removed.

Meyers allegedly told Mule that he placed the commode and an expensive rug in storage for safekeeping while he had the living room repainted as a gift to Barbara. Meyers also said he had a fake commode installed so the living room wouldn’t look odd.

The lawsuit says that at the time Barbara’s only son, Winthrop Paul Rockefeller, and his wife, Lisenne, accepted Meyers’ reason, believing the fake commode would avoid upsetting Barbara.

In spring 2005, as Barbara’s health declined, she accepted her son’s offer of moving in with his family at their Arkansas home. But shortly after her arrival, her son fell ill with a rare blood ailment and died at 57 in 2006. Barbara died two years later at 91 in Little Rock, Ark.

The lawsuit claims that after Barbara’s move, Meyers never contacted her. Lisenne Rockefeller said when her mother-in-law died, she tried to track down Meyers and the commode, but had no luck.

The lawsuit says Lisenne didn’t file a police report stating the furniture was stolen because she believed it would eventually be returned.

But in 2011 she learned that Meyers had been arrested on felony charge a year earlier for owing $220,927 in child support to his wife and kids in Michigan. A judge later sentenced him to three and a half years to 15 years in prison.

When Lisenne heard that the commode was up for auction, a family representative contacted Sotheby’s, who informed them of Whitfield. The art dealer told the family rep that he had bought the commode from Meyers in 2009, according to the lawsuit.

When he was told the commode was stolen, Whitfield noted the purchase had been “too good to be true” but refused to return it, the lawsuit claims.

Whitfield could not be immediately reached for a comment.

Anthony J. Costantini, a lawyer for Lisenne, said she filed the lawsuit after an agreement couldn't be reached with Whitfield.

He said the commode rightfully belongs to the Rockefellers. He noted that Barbara Rockefeller was an avid art collector who did at times approve the sale of some of her pieces — but her commode was off limits.

“She would from time to time sell some of her furniture,” he told DNAinfo.com New York. “But the commode was always verboten. She never wanted to offer that for sale.”

The lawsuit says that Sotheby’s is currently in possession of the commode and stated it would hold on to the furniture until the matter is resolved.