Sydney: A man who publicly accused Australia’s most senior Catholic cardinal, George Pell, of child sexual abuse has died following a long illness.

Damian Dignan, who lived in the Victorian town of Ballarat, made allegations which were strenuously denied by Pell.

Dignan was one of a number of complainants who made allegations against Pell of historical sexual offences.

Dignan’s death was confirmed by his former partner, Sharon Rixon. “It is with great sadness that my best friend and the father of my children has passed away today,” she wrote on Facebook. “I will continue to love and guide and support our children through this difficult time.”

QC and former chief Victorian magistrate and crown prosecutor, Nicholas Papas, told Guardian Australia that Dignan’s death would affect the structure of Pell’s upcoming court case in Melbourne.

“The death of a witness if generally very serious and can affect whether the case proceeds or not,” he said. “But it’s not as simple as that, as there may be other evidence or witnesses. In a murder case, for example, the victim is obviously never there and yet a case can proceed. So it’s not that it’s unusual for witnesses to be dead, but in a case where an allegation involved historic sexual assault and there may be no other direct witnesses to that abuse, it can seriously affect the case.”

Dignan’s lawyer, Ingrid Irwin, told the Australian she was saddened and “gutted” Dignan would not be able to contribute to the case in person.

“It’s totally ridiculous that he’s now passed away without any justice, the legal system is completely inept and archaic,” she said.

“He is one of the bravest Ballarat boys I know, he walked around broken and somehow found the strength to speak out.”