The 54-year-old remains under guard in hospital following last week's attack at Kogarah, in which he also allegedly stabbed a man who confronted him.

He has now been linked to calls made to a woman at a southern Sydney business in late October.

Deputy Commissioner Jeff Loy on Wednesday admitted that police identified and interviewed the alleged offender about the call but there was "no action" taken - despite knowing he was on parole.

Police have now launched an internal investigation to see why it was not reported.

Asked whether the attack could have been prevented, Mr Loy told reporters in Sydney: "Nobody can predict the future or the future actions of any person."

Investigators are now appealing for anyone else who may have been contacted by the man to come forward.

His parole, which began in September 2017 after a jail term for a violent sexual assault in 2012, was revoked within hours of his arrest.

"He is a danger to the public and that's why he's under corrective services guard in hospital," the deputy commissioner said.

My Loy has personally contacted the parents of the child to tell them of the situation.

"They are very brave. They want to get their lives back in order."

Police Minister Troy Grant has urged the deputy commissioner to complete the investigation as soon as possible.

"The initial indications are that police could have done more, and if that is the case, I'll expect swift action to be taken," Mr Grant said in a statement.

NSW Corrections Minister David Elliott on Wednesday said he was "horrified" that the man had been granted parole.

He also took aim at the state's parole board.

"The mere fact that I have taken parole board decisions to the Supreme Court in the past is good evidence to suggest that I'm not comfortable with a lot of parole board decisions," he told reporters.

Opposition leader Michael Daley in question time called on Mr Elliott to divulge a preliminary report into to the circumstances behind the incident, which he described as "an appalling failure".

Mr Elliott confirmed he had received a preliminary briefing, but refused to outline what it contained because it could prejudice a looming trial.

"That would put this investigation into some question, it would certainly put into question any potential court proceedings that are coming," Mr Elliott told parliament.

"I cannot believe the man that professes to be the alternate premier in this state is actually asking me to provide information, put it into the public domain, which would put a criminal investigation into question."

Mr Elliott accused the opposition of politicising the attack.

"Right now there is a seven-year-old girl who has gone through the most traumatic of experiences," Mr Elliot told parliament.

Australian Associated Press