Six years after the search for Shannan Gilbert led to the discovery of 10 other sets of human remains near Gilgo Beach believed to be the work of one or more serial killers, a new documentary series to be screened at the Hamptons International Film Festival on Sunday attempts to examine why police have failed to solve the mystery.

Corruption at the top of the Suffolk County Police Department and prostitutes as victims are explored as barriers to cracking the notorious case in “The Killing Season,” an eight-part series that premieres next month on A&E.

Documentarians Rachel Mills and Josh Zeman spent four years off-and-on conducting interviews and tracking leads on Long Island from Massapequa to Oak Beach, with the Gilgo mystery serving as a centerpiece of the series that also explores serial killings of women in Atlantic City and New Mexico.

The Gilgo killings have garnered nationwide attention after detectives searching for Gilbert, a prostitute who disappeared in May 2010, discovered four women’s bodies in nearby Gilgo Beach seven months after she vanished and concluded it was the work of a serial killer. Other human remains were later found along nearby Ocean Parkway, which suggested to detectives there was more than one person responsible for the killings.

The television series takes aim at felon and former Suffolk Police Chief of Department James Burke — currently in federal custody awaiting sentencing on charges of violating the rights of a Smithtown man and then masterminding a cover-up of the crime — for preventing the FBI from working with police to solve the killings.

“It was unbelievable to us, that this was one of the largest serial killer cases in the United States and one of the bizarre and baffling but the fact that the FBI, the fact that Suffolk County didn’t have a full profile of this killer was shocking to us,” Zeman said in an interview.

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“One of the reasons this case did not get solved is because the Suffolk County Police Department did not bring in the FBI because of other nefarious activities that were going on within the Suffolk County Police Department,” Zeman added.

But John Meringolo, Burke’s Manhattan-based attorney, said in response to the claims: “It defies logic and common sense that any state or city or county law enforcement could impede an FBI investigation.”

Suffolk Police Commissioner Timothy Sini, who after taking the helm of the department in February invited the FBI to assist in the investigation, sat for an interview with the documentarians, who drew a parallel to the killings and Burke’s own past, which according to a previous Newsday report included dating a prostitute.

Zeman says to Sini: “You’re dealing with a chief of police who is supposed to be investigating a case of sex workers who has his own history with sex workers. So how do we disentangle that from this case?”

Sini responds: “Every day we do everything we can to solve it and that’s why I immediately got the FBI on board.”

While the documentarians said it was not their goal to try to solve the killings — which they say will probably only happen if police share clues with the public that may jog someone’s memory, or a scorned associate turns on the killer or killers — the series also looks at some of those who have been questioned by police, including Dr. C. Peter Hackett.

The last person known to have seen Gilbert, 24, alive before she apparently ran into the nearby marsh on May 1, 2010, Hackett, a former police surgeon now living in Florida, has been cleared by police.

Former Suffolk Police Commissioner Richard Dormer makes a brief appearance in a sit-down interview and proclaims that Shannan Gilbert was not a murder victim: “We still believe, and we hold to it, she succumbed to the elements.”

A Suffolk police spokesman declined to comment on the current state of the investigation Friday, citing the ongoing investigation.

The second episode opens with Shannan Gilbert’s funeral — and the sobs of her now-deceased mother, Mari Gilbert, who according to police was fatally stabbed in July by another daughter, Sarra Gilbert, in upstate Ellenville. Sarra Gilbert has pleaded not guilty, and her lawyer John Ray, who had represented the family in their fight for justice for Shannan, maintains she was suffering from mental illness at the time of the killing and therefore is not responsible for her actions.

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“This case continues to evolve,” Zeman said. “Look at what happened, the tragedy of Mari Gilbert, we interview her . . . and now she’s passed away. This is really just one of the most bizarre cases I’ve ever seen.”