Robert K. Wittman, the renowned undercover art sleuth who retired yesterday after 20 years with the FBI, vividly remembers the first art theft he helped solve.

In November 1988, a few days before Wittman arrived in Philadelphia fresh from the FBI Academy, a robber stole a bronze sculpture from the Rodin Museum on the Parkway.

Mask of the Man With the Broken Nose

was considered Rodin's first major work.

The thief, an unemployed dancer who Wittman said was "down on his luck," wrapped the 12-inch bronze in brown paper and hid it beneath a hot-water heater at his mother's house on Pine Street. That's where investigators found it a few months later.

"That was the beginning and end of his art career," said Wittman.

But Wittman's was off and running.

Over two decades, Wittman has helped recover more than a thousand artistic and cultural works, acquiring fame for his international derring-do as an undercover agent, posing as a shady fine-arts dealer or a corrupt academic. In 2005, he was named senior investigator of the FBI's new national Art Crime Team, based in Philadelphia.

His recoveries include a Rembrandt self-portrait stolen from a Swedish museum, one of the 14 original copies of the Bill of Rights, and five Norman Rockwell paintings recovered in a Brazilian farmhouse.

"I recovered over $225 million in stuff," Wittman, 52, said Thursday in his office overlooking Independence Mall. "I don't know how much more stuff I can get."

More than 100 friends and admirers gave Wittman a send-off banquet yesterday at Rosewood Caterers in Upper Holmesburg. But some old habits die hard. Wittman, who guarded his undercover identity to keep art thieves in the dark, still won't allow his face to be photographed, even in retirement.

That's because Wittman may still be called on to work undercover. He is planning a career as a private art-security consultant, working with galleries and individual collectors to recover stolen works, avoid fraudulent purchases, and learn prevention techniques.

"I'm not going to miss traveling to Spain or France or South America to do cases, though that was great. It was fun and I loved doing it," he said. "I'm going to miss all my friends, all these people here who've become my extended family."

Wittman already has several speaking engagements lined up. On Tuesday he will fly to Miami for a ceremony to mark the return of 200 Ecuadoran artifacts for which he posed as a cigar-smoking, Rolls Royce-driving art buyer. And next weekend, he travels to Italy to be the keynote speaker at the International Convention of Exhibition and Fine Art Transporters.

His new career also means he will be reunited with his longtime partner, Robert Goldman, a former assistant U.S. attorney who prosecuted many of the cases that Wittman investigated. Goldman, who left government service in 2006 and has established a fine-arts law practice in Philadelphia, plans to hire Wittman as an investigator.

"It'll be nice to be the Two Bobs again," said Goldman, who first met the FBI agent when they worked on a team that successfully prosecuted Philadelphia mobster Joseph Merlino for a 1987 armored-car heist.

Wittman's career as an art-crime investigator began by chance. Raised in Baltimore, he studied political science at what is now Towson University and went into business publishing agricultural newspapers with his brother. He entered the FBI Academy when he was 32.

His parents were antique dealers in Baltimore, which gave him insights into the art world that were useful as he developed his specialty.

"The business of art is different from the history of art or the appreciation of art," he said. "So, knowing the business of art is a specific talent."

An affable man of medium build and gray hair, Wittman said the secret to working undercover is not acting. "It's really being yourself, but assuming a role," he said. "You can't act 24 hours a day. Nobody can."

Wittman's fans say he has acquired a tremendous knowledge of art, and has developed a special rapport with museum curators, who he often calls upon for instruction on the finer details of art before posing as a buyer of such specialized works as Incan antiquities or Pueblo Indian ceremonial fetishes.

"He's completely unlike anything I expected," said Kristen Froelich, director of the collection at the Atwater Kent Museum. She got to know Wittman in 1997 when she worked at the Historical Society of Pennsylvania and the FBI recovered more than 200 items stolen by a museum janitor.

Wittman's colleagues say he is successful because he makes friends easily with criminals.

"I call him LB - Lovable Bob," said Special Agent Jerri Williams, the FBI's spokeswoman in Philadelphia. "He really is just a down-to-earth, friendly, easy person. I can see how a crook, in talking to him, is not going to be suspicious."

Wittman, a father of three who lives with his wife, Donna, in Garnet Valley, said the FBI's art-crime team will continue without him. The team, which has recovered 800 items and repatriated artworks to 10 countries, now has 13 agents stationed at FBI offices across the country.

But Goldman, the former prosecutor, said he is "pessimistic" that the FBI will continue to place as much emphasis on pursuing art crime after Wittman retires. "I don't think the government has got the heart to keep this thing going," he said.

That may only mean more demand for Wittman's skills. Art represents a $200 billion worldwide annual business, including about $5 billion in stolen, illicit or forged artworks. Just this week, Wittman noted, the British artist Damien Hirst raised $198 million in a two-day auction of his work in London.

"It shows you there's a lot of money, and the art industry is still well and alive," said Wittman. "People love art. The problem is, on the other side, it's an easy industry to be defrauded in."