Casey Anthony has never revealed who the father of her slain toddler daughter, Caylee was. Today, she still reportedly insists on keeping said dad private, despite rumors and speculation involving numerous men who reportedly could have been Caylee’s father.

“I don’t know who the father was,” an undisclosed source close to Anthony told PEOPLE. “She doesn’t talk about it. She will never tell anyone. She’ll take that secret to the grave.”

For many years, a man simply known by the name of “Josh” was speculated to be the father of Caylee. Josh tragically lost his life in a car crash in 2007. Anthony’s friend, Melina Calabrese, was one of the people who claimed Josh to be the dad, but she also claimed Anthony worked with him at Universal Studios and had a “one night stand” with him. According to Calabrese, Anthony told her former fiancee that “a really hot guy” was the biological father of her child.

Authorities later determined Anthony lied to them about working at Universal Studios when Caylee disappeared. While Casey did indeed work at Universal Studios at one point in time, she was fired in April, 2006, a year prior to Caylee’s disappearance. While it’s possible she may have met someone while working there in 2006, no evidence supports the theory of “Josh,” whose last name was never given.

Another man, Michael Patrick Duggan, who ironically also died in a fatal car crash, was also rumored to be Caylee’s father. Duggan’s own mother, Donna MacLean, said that her son told her he had a daughter, according to The Daily Beast.

“I asked him about the circumstances… who is the family? He said the parents were George and Cindy Anthony. I asked who she was and he said her name is Casey.”

Within weeks of the conversation with his mother, however, Duggan passed away. With only MacLean’s word and Duggan’s half-brother word that he vaguely remembered hearing something about it, nothing ever became of the rumor.

Another rumored father was Jesus Ortiz. Anthony’s mother, claimed that Ortiz was father, but according to In Touch Weekly, the man’s family denied, stating he nor Anthony never said a word about it.

Another man, Eric Baker, who also died in a crash crash, was another rumored to be the father. Eric’s name was briefly mentioned during Anthony’s murder trial,  but subsequently dropped when his mother testified Baker was only a teen when Caylee was conceived.

Anthony’s former fiancee, Jesse Grund, assumed the role of father to little Caylee during most of her young life. Although he seemed to be most likely candidate, a paternity test confirmed he was not the father.

“Um, well, at first I thought it was Jesse. I don’t know his last name,” Anthony’s friend, Lauren Gibbs, told authorities. “But um, and then she told me later that it was not and that it was somebody who was in the Army or something like that. But then she told me that he had died last year in a car accident.”

The source close to Anthony reiterated that the infamous woman would likely never tell anyone, and at this point, the public is not any closer to knowing. The source insinuated that Anthony herself may not be 100% sure who the father was.

“If she knows who the father is, she’s not telling. She definitely won’t ever say anything publicly. I doubt anyone will ever know.”

[Feature Photo: Caylee Anthony/Handout]