NEW YORK — New York City has denied another request for data about the toxins that swirled above Ground Zero after 9/11 — claiming nothing could be found — despite the discovery of 68 boxes worth of information on the subject just four months ago, the Daily News has learned.

Advocates for 9/11 survivors are again suing for the data, claiming city officials are playing hide and seek with people’s lives.

“With its ever-changing replies, the city plays three-card monte with Sept. 11 records,” attorney Andrew Carboy said about the stream of Freedom of Information Law denials.

Carboy filed a new lawsuit against the city on Sunday, asking a judge to order the city to produce the records. A similar lawsuit against the city’s Department of Environmental Protection led to the agency coughing up 68 boxes worth of material on the subject, despite the city claiming for years it had nothing to share.

Those documents included a memo ordering all agencies to send their documents regarding 9/11 to the Law Department.

To Carboy, the latest denial was the same song advocates have heard for nearly a quarter century — but this time with a different dance partner: Mayor Zohran Mamdani.

In the lawsuit, Carboy and attorney Matthew McCauley, who are representing the families of 9/11 illness victims and the survivor advocacy group 9/11 Health Watch, said that the city closed a 2023 FOIL request for the data sent to the mayor’s office and the city Law Department, as well as two appeals for the data. The last appeal was denied on March 20.

In the denial, FOIL Appeals Officer Jeffrey Lowell, claims that searches “have not identified any records responsive to your requests under FOIL,” according to court documents.

Lowell also claimed that “the Law Department records are not maintained in a manner that allows it to search for records responsive to the request.”

The denials came in February, three weeks after incoming Corporation Counsel Steven Banks testified before City Hall and vowed to review all of the 9/11 related documents the city has and “release or make available what can be made available,” the lawsuit states.

“Even as a new Corporation Counsel pledges ‘transparency’ and the release of the Sept. 11 archive, in the corridors of the Law Department and the dimmer corners of City Hall, career officials continue their grinding resistance,” Carboy says in the new lawsuit.

“City Hall treats the Freedom of Information Law like a rigged card game, staged atop a cardboard box on a sidewalk. Here, Sept. 11 first responders and survivors, seeking the facts of toxic exposure, are the ‘marks,’ left without answers after tireless efforts to obtain them.”

“[The city’s] shameful achievement is to make records of the most significant event in New York City history ‘disappear,'” he added in the suit. “The FOIL appeal denial from their government might as well read ‘Thanks for playing.'”

The city, in its search for documents, sent 911 Health Watch internet links to widely available, decades-old federal reports and testimony.

“The head-snapping ‘back and forth’ between city leaders and city lawyers, an effort to prevent any substantive disclosure, is highly improper,” Carboy says in the suit. “This sleight of hand must stop now.”

An email to the Law Department about the FOIL denial and Carboy’s lawsuit was not immediately returned.

“Transparency isn’t optional, it’s essential to any healthy democracy,” a spokesman for the mayor said in a statement.

“Mayor Mamdani has been clear — transparency and accountability are prerequisites to a city government that truly delivers for New Yorkers. Based on this responsibility, this administration is working to address FOILs, including this request, in a timely and efficient manner.”

With the city marking the 25th anniversary of 9/11 in five months, Benjamin Chevat, the executive director of 911 Health Watch, is hopeful Mamdani will bring about a change.

“Mayor Mamdani can still be the who, after 25 years, answers the question: what did the city know about the hazards caused by the toxic chemicals at Ground Zero, and when did it know it?” Chevat said Sunday.

More than 140,000 first responders and survivors are now enrolled in the U.S. Center for Disease Control’s WTC Health Program, which provides 9/11-related health care benefits. Out of that number, about 81,000 have a certified condition linked to the toxins that hung above Ground Zero.

On the day of the terror attacks, 343 FDNY members died in the collapse of the twin towers. Since then, an additional 400 members have died of 9/11-related illnesses.

City administrations dating back to Mayor Rudolph Giuliani have refused to provide attorneys and local elected officials documentation on what city officials knew about the potential dangers of World Trade Center toxins.

The stonewalling continued until last year when City Councilwoman Gale Brewer, D-Manhattan, pushed through legislation ordering the city’s Department of Investigation to launch a probe over what and when the city knew about the toxins.

A Daily News story published last year as the city marked the 24th anniversary of the terror attacks disclosed that only eight weeks into the DOI review, the response was so overwhelming the agency was looking at the possibility of getting outside help to parse through all the data.

Then, after telling Carboy that they had no documents to share — and even petitioning the court to dismiss the attorney’s FOIL requests, calling the search nothing more than a “fishing expedition” — the city Department of Environmental Protection late last year suddenly produced 68 boxes of materials for attorneys to sort through.

After years of searching, Carboy and his team in February obtained a copy of the famed “Harding memo,” which was written about a month after 9/11. In it, city officials raised concerns that thousands of first responders and survivors could potentially suffer from “toxic exposure” at Ground Zero.

Carboy and McCauley repeatedly asked the city for a copy of the memo, only to be denied. They finally got a copy from the Dolph Briscoe Center for American History at the University of Texas at Austin, where the estate of investigative Village Voice journalist Wayne Barrett, who had cited the Harding memo in his 2007 book “Grand Illusion,” had bequeathed his personal papers and notes.

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