Chief Minister Andrew Barr and Attorney-General Shane Rattenbury revealed the scope of the high-profile Parliament House rape case probe on Wednesday, when they also confirmed it would be led by retired Queensland judge Walter Sofronoff KC.

Mr Sofronoff, a former Queensland Court of Appeal president, will look at whether police officers and the ACT Director of Public Prosecutions breached, or failed to act in accordance with, their duties.

If he finds they did, the respected legal figure will examine "the reasons and motives for their actions".

The government also revealed Mr Sofronoff would inquire into the circumstances surrounding the release of a letter that made the public aware of tensions between police and prosecutors, and which cast a shadow over the integrity of the territory's criminal justice agencies.

Mr Barr and Mr Rattenbury first announced the board of inquiry in December, when the Attorney-General said the territory government was "deeply concerned" by explosive allegations of misconduct.

Calls for an inquiry had been mounting at the time, following the release, under freedom of information laws, of a letter written by ACT Director of Public Prosecutions Shane Drumgold SC.

In the November 2022 letter to ACT chief police officer Neil Gaughan, who has privately told his officers he was not consulted before its public release, Mr Drumgold made the extraordinary claim investigators had unsuccessfully pressured him not to prosecute Bruce Lehrmann.

Mr Drumgold alleged police then aligned themselves with the defence of Mr Lehrmann, who has always denied raping Brittany Higgins at Parliament House when the pair were Liberal Party staffers in 2019.

After Mr Lehrmann's ACT Supreme Court trial was aborted last October because of juror misconduct, Mr Drumgold dropped the case as a result of fears about the impact a retrial would have on Ms Higgins' mental health.

The government previously said the inquiry would examine the ACT's legal framework for dealing with juror misconduct.

However, Mr Sofronoff did not believe this was an appropriate subject for a board of inquiry and it will instead be considered separately by the government.

The inquiry will still look at whether the support ACT Victims of Crime Commissioner Heidi Yates provided Ms Higgins during the trial was appropriate, given the presumption of innocence afforded to Mr Lehrmann.

Mr Barr, who anticipates receiving the inquiry's findings in the first half of 2023, said on Wednesday its report would likely be made public in early August.

He described the allegations and complaints made about the ACT's criminal justice agencies as serious.

"Mr Sofronoff is a highly regarded legal expert with experience leading sensitive inquiries throughout his career," he said.

"He was also Queensland's solicitor-general for almost 10 years. I am confident that Mr Sofronoff will deliver a thorough and respectful independent inquiry."

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Mr Rattenbury said the inquiry was established to ensure the territory's framework for progressing criminal investigations and prosecutions was "robust, fair and respects the rights of those involved".

"It is important to remember that this will not be a retrial of the case," the Attorney-General said.

"It will focus on whether the criminal justice officials involved performed their duties with appropriate rigour, impartiality, and independence."

It will be up to Mr Sofronoff, who is currently on an overseas holiday, to determine whether the inquiry holds public hearings.

Mr Rattenbury said he had conveyed to the inquirer "the government's desire to bring sunlight to this matter [and] be transparent about it".

"It's important for our community to have confidence that people are doing their role appropriately," he said.

ACT Opposition Leader Elizabeth Lee again criticised the government for not explicitly outlining an intention to have the inquiry examine claims of "political interference" in the case, which Mr Barr described as being "laced with politics".

Ms Lee said the failure to explicitly identify possible political interference in the terms was "startling" and indicative of the government not taking it seriously.

However, Mr Rattenbury indicated the inclusion of "motives" for possible misconduct in the terms of reference ensured such allegations could be examined if police or Mr Drumgold were found to have acted inappropriately.

Ms Lee also blasted the ACT cabinet for recently reappointing Ms Yates for a further five years despite the Victims of Crime Commissioner's conduct being one of the inquiry's subjects.

She denied the government would have been pre-empting the inquiry's findings if it had not extended Ms Yates' appointment.

Policing figures reacted positively on Wednesday to the latest developments surrounding the inquiry, with Deputy Commissioner Gaughan describing Mr Sofranoff as "extremely well-credentialed".

"We're basically ready to work with the inquirer and his team to provide answers to a lot of those questions that have been asked not just by my members, but by the broader community," the police chief said on ABC radio.

He added that ACT Policing's relationship with the territory's prosecutors remained strong, revealing he and Mr Drumgold had been exchanging text messages on Tuesday night.

Australian Federal Police Association president Alex Caruana also welcomed Mr Sofranoff's appointment, and called the terms of reference "reasonable".

He noted, however, that the terms did not focus on the actions of the Attorney-General, and called for an examination of his "rush" to amend laws about the reuse of video evidence before plans to try Mr Lehrmann again were scrapped.