So far the NYPD has refused to turn over any information for examination

The scanner uses low-level radiation technology similar to that banned at airports in Europe in 2011

A state judge has ordered the NYPD to turn over records about an X-ray van program the department has kept shrouded in secrecy.

New York State Supreme Court Judge Doris Ling-Cohan wrote in a decision back in December that radiation used in the vans raised concerns over health risks and said the department's claims about information being used by terrorists to evade detection was 'mere speculation.'

For years, the New York Police Department has deployed unmarked white vehicles known as Z-backscatter vans used to detect bomb-making equipment, narcotics and other material.

Ordered: A state judge ruled the NYPD must turn over records about a program using X-ray vans, similar to that pictured here, that the department has kept shrouded in secrecy

But the NYPD has refused to make details of the program known to the public about how the department uses the vehicles to conduct searches, raising privacy concerns.

The low levels of radiation emitted by backscatter technology has also been shown to mutate DNA and thus increase the risk of cancer, which led the EU to ban backscatter technology in European airports back in 2011.

The danger posed by the type of radiation used in the scanners is not known, though studies suggest even at low levels, it can increase cancer risk, especially through prolonged exposure.

The scanners emit a 40 percent higher dose of radiation than an airport backscatter scanner, according to the court decision.

Though little is known about how the NYPD deploys the vans, they made an appearance in the book Bomb Squad, written by two investigative reporters from ABC.

The book describes how, during the 2004 Republican national convention in New York, drivers turning onto a street by the venue had to pass through two X-ray vans that scanned cars for explosives.

Revealing: A photo on the website of AS&E shows how the technology can be used to reveal contraband, such as smuggled bottles of alcohol

Scanns: The technology can also be used to spot materials like hidden currency, though reports say the NYPD uses scanners to detect bomb material

The December ruling to release documents came after almost three years of legal wrangling by investigative reporting outfit ProPublica.

In February 2012, the outlet filed a petition under the Freedom of Information Law, or FOIL, for the NYPD to provide documents relating to the Z-backscatter vans.

It asked for information on police procedures, training documents, purchase records and safety tests, as well as legal decisions or interpretations used by the department to support the deployment of vans.

The outlet also requested information on data produced by the scanners and stored by the NYPD, along with the image scans still held by the department.

The department refused, with former NYPD deputy commissioner of counterterrorism telling the court in 2013 that revealing the information would put New Yorkers at risk.

The release of records would 'permit those seeking to evade detection to conform their conduct to the times, places and methods that avoid NYPD presence and are thus most likely to yield a successful attack,' Daddario said.

Judge Ling-Cohan said the claim was 'patently insufficient' to justify withholding information, considering the risks to both health and privacy.

'This court is cognizant and sensitive to concerns about terrorism, being located less than a mile from the 9-11 site, and having seen first-hand the effects of terrorist destruction,' Ling-Cohan wrote in her decision.

'Nonetheless, the hallmark of our great nation is that it is a democracy, with a transparent government.'