However, a coroner on Tuesday said there was insufficient evidence for a strong circumstantial case against another daughter of Mr Ball and her husband.
Family friend Brian Murphy told a re-opened inquest into Mr Ball's disappearance last year that David Phillips confessed in the 1990s to killing his father-in-law.
He said Mr Phillips - who died in 2015 - told him he bashed the 71-year-old at his north Queensland home then found someone who "looked remarkably like his father-in-law".
He recruited the lookalike so a neighbour thought it was his father-in-law when they saw them going back to the Townsville house, the inquest was told.
Mr Phillips told him they took the body away in a truck before he killed the lookalike and buried him with Mr Ball, Mr Murphy said.
Ms Lesley and her mother Ett Ison made lengthy written submissions on why the court should find that Mr Ball died by an "act of violence" and that either Mr Phillips was responsible or he and his wife attempted to conceal the death, coroner Stephanie Gallagher said.
"However, I do not accept the submission that the evidence amounts to a strong circumstantial case," Ms Gallagher said on Tuesday, handing down her findings.
"There are other possibilities open on the evidence and is presently insufficient evidence on which to make any conclusive findings other than Mr Ball is deceased and that another person or persons unknown may have been involved in his death."
Ms Gallagher noted that Ms Lesley had never given up on getting answers since reporting her father missing in 1993.
"The evidence at inquest ... is insufficient for this court to make firm findings in respect to what happened to Mr Ball," she said.
"This is an unfortunate situation and clearly a very distressing one for Mr Ball's family, particularly his daughter Le-Chelle who has not stopped trying to find out what happened to her father."
Outside court Ms Lesley told media: "Blind Freddy could see (what happened to Mr Ball)".
Detective Senior Sergeant Chris Knight told the reopened inquest last year that he believed Mr Phillips had some involvement in World War II veteran Mr Ball's disappearance and had "constructed lies" with his wife.
Leanne Phillips denied any involvement in her father's disappearance, telling the inquest that the last time she saw him was when he visited her in a Brisbane hospital in April 1993.
However, Det Sen Sgt Knight said experts had confirmed a train ticket from Townsville to Brisbane discovered in Mr Ball's name was a forgery.
Mr Ball's car was found at the Townsville Railway Station and his trailer was burnt out in bushland, the inquest heard.
Ms Gallagher said on Tuesday it was likely Mr Ball died in or around Townsville on or around April 18 1993 but it was not possible to determine the cause of death.
"There's no results as far as I'm concerned today ... but life goes on," Ms Ison said outside court.
15°C