Aaron M. Freedman spent nearly 20 years managing the fine details of life at Subhash Kapoor’s art gallery on Madison Avenue in Manhattan. Over that period, ending in 2012, the two men became good friends, shared an expertise in rare Indian artifacts and co-wrote several scholarly works.
On Wednesday, Mr. Freedman, 41, of Princeton, N.J., admitted in New York Supreme Court that he also helped Mr. Kapoor manage the shipment and sale of more than 150 items of looted Indian statuary, items in many cases dating back some 2,000 years.
Mr. Freedman pleaded guilty on Wednesday to six counts of criminal possession of stolen property valued at $35 million and agreed, under his plea, to help Manhattan and federal investigators with their prosecution of Mr. Kapoor, who is accused of smuggling more than $100 million in antiquities from India into the United States.
Mr. Kapoor, 64, is in prison in India but is expected to be extradited for trial in the United States next year.
Investigators are still hunting for dozens of the bronze and sandstone images of Hindu and Buddhist deities that they say were looted and sold over three decades under the supervision of Mr. Kapoor and his confederates.
Storage facilities associated with Mr. Kapoor were raided in 2012 by federal agents, and his gallery, Art of the Past, on Madison Avenue at 89th Street, is no longer operating.
“He is by far the biggest smuggler, in terms of numbers of antiquities stolen and their market value, that we have seen,” said James T. Hayes Jr., the special agent in charge for Homeland Security Investigations in New York.
The authorities said that Mr. Freedman handled the day-to-day details of the gallery for Mr. Kapoor, while also helping to pay off smugglers, concoct false shipping and ownership papers, and arranging for sales to often unsuspecting collectors and museums.
On Wednesday, Mr. Freedman told State Supreme Court Acting Justice Charles H. Solomon that his multiple sclerosis was diagnosed in 2005 and that his condition worsened while he worked with Mr. Kapoor.
“I say this not to excuse my involvement with Mr. Kapoor’s criminal activities,” Mr. Freedman said, “but to state that in 2005, after the onset of my disease, obtaining employment at a reputable gallery or auction house was virtually impossible.”
The Manhattan district attorney’s office, which is working with federal officials on the case, agreed to release Mr. Freedman on personal recognizance while his cooperation continues.
“We take these crimes very seriously, and as the office manager for Mr. Kapoor, he was the one who made much of it happen,” said an assistant district attorney, Matthew Bogdanos. “On the other hand, Mr. Freedman, I believe, is sincerely and genuinely remorseful and repentant and he has taken significant steps toward making amends.”
Under India’s Antiquities and Art Treasures Act, no art object more than 100 years old may be removed from the country. But since the law was instituted in 1972, antiquities from many Indian temples and heritage sites described as “newly discovered” have been auctioned in New York and London. In four raids at separate sites controlled by Mr. Kapoor in 2012, federal agents say they seized about 90 items worth, in total, more than $100 million, all of them having come out of India after 1972. Another 50 or so items valued at more than $40 million remain missing, and investigators are asking the public to help locate them.
One of the items Mr. Freedman is accused of helping steal and conceal is valued at $15 million and is among the rarest and most cherished statues missing from India. Identified as the sandstone statue of a Yakshi, or female deity, from a stupa temple site in Bharhut, in Madhya Pradesh province in central India. It is more than seven feet tall and weighs about 500 pounds. Indian scholars say the stupa of Bharhut is one of the most important Buddhist sites in the world.
In a sales brochure for the statue that was sent by Mr. Kapoor to private buyers, Mr. Freedman wrote: “This sculpture is the most significant example of Indian sculpture known to exist outside of India. It is of pivotal importance to the understanding of the Bharhut stupa, and to the entire development of Indian art.”
Indian officials said that they hoped the relic would be repatriated early next year. It is now being held in New York.
Paul B. Bergman, Mr. Freedman’s lawyer, said his client was eager to “take concrete steps to rectify his serious mistakes.”