A newfound set of human remains discovered this year brought renewed hope to the family of missing teenager Natalee Holloway. The bone fragments, found in Aruba, were located thanks to a private investigation launched by Natalee’s father. Months of DNA testing, however, revealed the remains did not belong to Natalee.

The retrieval of the remains was announced in August. They were then sent to a laboratory for analysis to determine whether they belonged to the teen. But DNA testing ultimately proved the remains did not belong to Natalee, lead forensic scientist Dr. Jason Kolowski confirmed to Oxygen Monday.

“Out of four individual bone samples, only one was found to be human,” said Kolowski. “The mitochondrial DNA bone sample was not a match to [mother] Beth Holloway and so it was ruled out as being Natalee Holloway.”

GettyImages-101885424 Beth Holloway launches the Natalee Holloway resource center in Washington, D.C., Jun. 8, 2010. Photo: Getty Images

Preliminary testing on the remains revealed they belonged to a Caucasian person of European descent, sparking hope that they might be Natalee’s. The identity and gender of the person whose remains they actually were is still unknown.

“We don’t know how old that person is,” said Kolowski. “We don’t know how long that person has been dead.”

Natalee was 18 when she went missing during a class trip to Aruba in 2005. Though she was officially declared dead in 2012, her body was never found and nobody was ever charged with killing her. The primary suspect is still Joran van der Sloot, a Dutch man who remains behind bars in Peru for the murder of a different young woman. Her family accused Aruban authorities of botching the investigation by not going after van der Sloot more aggressively.

“They took their eyes off the last people that were known to be with Natalee,” her father, Dave Holloway, told Nancy Grace on “Nightline” in August.

In an effort to uncover the truth and find their daughter, Natalee’s family undertook an investigation of their own. The newfound remains were located through a joint 18-month investigation led by Dave Holloway private investigator TJ Ward. In the investigation, a friend of van der Sloot’s said the man paid him $1,500 to help dig up her remains and cremate them, leading them to these new human remains. Dave Holloway called it “by far the most credible lead” he had seen in the last 12 years.

Authorities in Aruba, however, pushed back against the idea that the human remains belonged to Natalee from the start.

“During an investigation by police in the area indicated by Mr. Holloway, we found remains, but they were found to be from animals,” Aruba Public Prosecutor Dorean Kardol told HuffPost in August.

GettyImages-136945498 Joran van der Sloot, shown here in court in Lima, Jan. 13, 2012, remains the primary suspect in Natalee Holloway's disappearance. Photo: Getty Images