(CNN) It's known as the Gilgo Beach murders, an unsolved case that has dredged up at least 11 human remains since 2010 and led to the hunt for a possible serial killer in suburban New York.
On Thursday, Suffolk County police on Long Island released photos of what it said could be a significant piece of evidence: a black leather belt embossed with the letters "WH" or "HM" that was found at one crime scene nearly a decade ago.
"We believe the belt was handled by the suspect and did not belong to any of the victims," Suffolk County Police Commissioner Geraldine Hart told reporters.
"We are hopeful that this photograph will bring somebody forward with information about the origins of that article."
Police also launched the website www.gilgonews.com to collect new tips and information about the murder investigation.
"It is important that the families of these murder victims know we remain steadfast in our commitment to deliver justice," Hart said.
The first set of female bodies were discovered by police in 2010 among the bushes along an isolated strip of waterfront property on Gilgo Beach while searching for Shannan Gilbert, a missing 24-year-old woman from Jersey City, New Jersey.
By the time Gilbert's body was found one year later on neighboring Oak Beach, Long Island, investigators, including the FBI, had unearthed 10 sets of human remains strewn across two Long Island counties.
Police said many of the victims identified had advertised prostitution services on websites such as Craigslist.
No arrests have been made in the slayings, and authorities have offered conflicting theories about whether a serial killer was responsible.
In 2016, the findings of an independent autopsy on Gilbert were found to be "consistent with homicidal strangulation," according to a report released her family's attorney, John Ray.
Her remains were discovered in a marshy area nearly 20 months after she vanished in 2010, police said. Oak Beach is about 9 miles from where 10 other sets of human remains were found.
Gilbert's family has long maintained that she died at the hands of a serial killer, but the theories offered by authorities have included a drowning and drug overdose.
Though Gilbert's death certificate listed the cause and manner of death as "undetermined," an independent autopsy by former New York chief medical examiner Michael Baden concluded "there is no evidence that she died of a natural disease, of a drug overdose or of drowning."
"There is insufficient information to determine a definite cause of death, but the autopsy findings are consistent with homicidal strangulation," Baden wrote in the report released four years ago.
Baden wrote that nearly all of Gilbert's recovered skeletal remains appeared normal but the "larynx was missing and only the body of the hyoid bone was found; the two greater horns of that neck bone were missing. These structures, the larynx and the hyoid bone, are often fractured during homicidal manual strangulation."
Ray, the attorney for the Gilbert family, on Thursday reiterated his call for police to release a recording of a 911 call Gilbert made when she disappeared.
Gilbert, 24, vanished after visiting a client, according to police.
The search for Gilbert led police to four bodies stuffed in bushes along a quarter-mile stretch of Ocean Parkway in Oak Beach. All four were later identified as women who had advertised online for prostitution services.
The bodies were found in various stages of decomposition.
Additional remains were later uncovered in neighboring Gilgo Beach and in Nassau County, about 40 miles east of New York City.
In December 2015, Suffolk County Police announced the FBI had joined the Gilgo Beach investigation.