Independent inquiry to be held into handling of Brittany Higgins’ allegations against Bruce Lehrmann

The ACT government has launched an inquiry into the case of Bruce Lehrmann after explosive allegations the police "aligned" with the defence in his trial for the alleged rape of Brittany Higgins.

The Australian Capital Territory chief minister, Andrew Barr, and the attorney general, Shane Rattenbury, announced the probe on Wednesday, three weeks after prosecutors said they would not pursue a retrial as it would pose an "unacceptable risk" to Higgins' health.

In a statement the pair said after a "number of complaints and allegations" about the trial the ACT government established a board of inquiry to consider engagement between the ACT director of public prosecutions (DPP) and ACT policing, "aspects" of their conduct, the role of the victims of crime commissioner, and the framework for juror misconduct.

"This was a high-profile trial," Barr said. "The allegations made in recent weeks are serious. An independent review of the roles played by the criminal justice agencies involved is the most appropriate response."

The ACT government is still seeking a legal expert to conduct the inquiry, which will report in the first half of 2023. ACT policing, the DPP and victims of crime commissioner have all indicated their intention to cooperate.

Lehrmann maintains his innocence to allegations that he raped Higgins, a colleague and fellow political staffer, in the office of the then defence industry minister, Linda Reynolds in March 2019. He pleaded not guilty to one charge of sexual intercourse without consent, denying that any sexual activity had occurred.

The Lehrmann trial was abandoned in October after a juror brought in outside research papers on sexual assault.

Earlier in December, Guardian Australia revealed that the chief prosecutor complained that police officers engaged in "a very clear campaign to pressure" him not to prosecute Lehrmann, saying there was "inappropriate interference" and he felt investigators "clearly aligned with the successful defence of this matter" during the trial.

Those claims were contained in a letter sent to the ACT's police chief in early November by the director of public prosecutions, Shane Drumgold SC, obtained under freedom of information.

The allegations have already been referred to the federal integrity and corruption watchdog for law enforcement, as ACT policing is a branch of the Australian federal police.

The Australian federal police association has rejected "smears" against investigators and thrown its full support behind calls for an inquiry, saying it must also consider the conduct of the DPP.

Rattenbury said the investigation "is not about revisiting the trial, any evidence in the trial or the outcome of the trial".

"It is expected that the inquiry will have regard to investigations which other bodies may be conducting regarding these matters," he said.

"I would ask everyone to respect the privacy of individuals who will be involved in this inquiry."