The Worcester Art Museum has transferred a Roman bronze bust — estimated to be worth about $5 million — to the Manhattan District Attorney’s Office following “new information” that the artwork was “likely stolen and improperly imported.”

The art museum sent out a press release Friday about the transfer of the bust, known as Portrait of a Lady, to be repatriated to Turkey, where it is believed to have been looted from an emperor’s family shrine.

The museum says it purchased the nearly 2,000-year-old object, thought to be a representation of a daughter of an emperor, in 1966. Leaders of the museum say they found out only in early 2023, through law enforcement in New York, that the object likely was stolen. “The museum had never previously received a claim or learned of any defect in ownership,’’ the press release said.

“We are very thankful for the new information provided to us,” said Matthias Waschek, the Worcester Art Museum’s Jean and Myles McDonough Director. “The ethical standards applicable to museums are much changed since the 1960s, and the Museum is committed to managing its collection consistent with modern ethical standards.”

But several researchers told GBH News they were dubious that the Worcester museum was just learning about concerns over the purchase of the life-size piece. The artwork was sold by Robert Hecht, now deceased, who was banned from Turkey in 1962 because of alleged looting, interviews and documents show.

Elizabeth Marlowe, a professor of art history at Colgate University who has long studied the Turkish site known as Bubon, where the statue apparently originated, said Worcester would have known when they bought the sculpture in 1966 that Hecht was “a totally shady character.” She also said the object was included in a list published in 1980 of bronzes known to have been acquired from Bubon.

“In 1966, Worcester knew that this piece was rumored to be from Turkey and they bought it from somebody whose activities in Turkey were such a violation of Turkish law that he had been banned,’’ she told GBH News. “They’ve been pretending not to know where this came from for a very long time.’’

Erin Thompson, a professor of art crime at the John Jay College of Criminal Justice, told GBH News that she too was dubious about claims from the museum’s leaders that they were just learning about concerns about the bronze, considering Hecht’s reputation. “Saying they only just now got new info that made them suspect it was stolen is like Pablo Escobar giving you a big pile of white powder and claiming you had no suspicion it could be drugs,’’ she said.

Nobody from the Worcester Art Museum could be reached for comment Monday.

A spokesperson from the Manhattan District Attorney’s Office says the Worcester piece is one of “multiple” pieces connected to alleged thefts from Bubon and trafficked through Manhattan. A headless bronze, estimated to be worth $20 million, has been seized from the Cleveland Museum of Art, and is “awaiting transport to New York,” the spokeswoman said. Other pieces in the ongoing investigation have already been repatriated.