It's been 10 years since Caylee Anthony's remains were found in a trash bag near her family's home — but people still have questions surrounding her death, like who is Caylee Anthony's father? While many of the details surrounding Casey Anthony's trial are clouded in mystery, this one is arguably the most intriguing of all. But true crime aficionados aren't the only ones in the dark about Caylee's paternity —and sources close to Casey revealed that not even the people closest to her know.

"I don’t know who the father was. She doesn’t talk about it. She will never tell anyone. She’ll take that secret to the grave," an insider revealed to People, and hinted that Casey might not even be sure who was her baby daddy. "If she knows who the father is, she’s not telling."

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Caylee with her maternal grandma.

While we may never know for sure who is responsible for Caylee's paternity, several men have either come forward or been named as possible contenders. Keep scrolling below to learn more about the men who could be Caylee's biological father.

Jesus Ortiz

Shortly after Caylee went missing, her maternal grandma, Cindy Anthony, told the media that "Caylee's father was in a terrible car accident, he is deceased" — and one person fit the bill, 21-year-old Jesus Ortiz, who Casey had casually dated before his death in 2007 died from injuries sustained in an automobile accident). Casey herself reportedly told friends that her former high school classmate was the father of her child.

When his family heard the news, they were shocked — since they claim Casey never hinted at the possibility that he fathered her child until after she entered the public eye because of her daughter’s disappearance, death, and subsequent trial.

"Miss Anthony never told the family Jesus was the father or that he might be the father," the family said in a statement. "In fact, the family has never met her and does not know her."

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Casey while on trial for her daughter’s death.

A colleague named Josh

A woman named Melina Calabrese — a friend of Casey — testified that Casey confided in her that she became pregnant after having a one-night-stand with a man named Josh, who worked at Universal Studios alongside Casey. According to Casey's pal, he also died in a car crash in 2007.

Of course, it was later revealed that Casey was lying to police about working at Universal Studios.

Eric Baker

Eric Baker is another candidate, who — tragically — met his demise in a 2007 car crash. During the trial, Cindy Anthony testified that an Eric Baker from either Kentucky or North Carolina fathered her granddaughter. When Eric Baker's mother heard this, however, she said that she had never heard of Casey before her son's name was dropped during the testimony — adding that her son would've been a teenager at the time Caylee was conceived.

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Jesse and Casey during happier times for the couple.

Jesse Grund

Jesse Grund was once engaged to Casey — and during much of her pregnancy and nearly all of little Caylee's life, he assumed the role of father, after Casey told him the baby was his even though the timing of her conception didn't quite line up with their relationship. Eventually, a DNA test confirmed that he was not the father.

"I petitioned for a paternity test, and there was a zero percent probability," he said on the Today show. "My attitude was, until the paternity test comes out, I'm not going to waste time or miss out if this really is my child."

Lee Anthony

During the trial, Casey's own brother was brought on the stand to testify and had to submit a DNA test to confirm that he wasn't the child's father. Fortunately, the DNA test confirmed that he was not Caylee's father.

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Casey’s parents, George and Cindy.

George Anthony

Casey's defense attorney, Jose Baez, also had Casey's own father submit a DNA test to prove he didn't father Caylee after making multiple allegations that he began sexually assaulting his daughter at a young age. While the paternity test confirmed he didn't father Caylee, Baez has continued to allege that the former law enforcement official "regularly abused" his daughter until she was 12.

Michael Duggan

Perhaps the least likely candidate is Michael Duggan — another young man who sadly died in a car accident in 2007. His mother, Donna, came forward during the media circus surrounding Casey's murder trial to say that, prior to his death, her son confided in her that he had a daughter with Casey.

While no one responded to Mrs. Duggan's allegations, she previously told The Daily Beast she is "100 percent certain" Caylee is her granddaugher.

Relive Caylee’s short but sweet life in the gallery below!