A former senior judge who headed a review into Bruce Lehrmann's rape trial gave rise to a sense of bias, a court has ruled.
Walter Sofronoff KC, who had been president of Queensland's Court of Appeal, was tasked in 2023 with examining the role of police and prosecutors in the high-profile case.
Though the inquiry's final report vindicated investigating officers, it found the ACT's former top prosecutor Shane Drumgold had engaged in malpractice and unethical conduct.
Mr Drumgold launched legal action in August to invalidate the adverse findings against him, with his lawyers claiming Mr Sofronoff's communications with The Australian's columnist Janet Albrechtsen had "infected" him with bias.
And on Monday, Justice Stephen Kaye said Mr Sofronoff's behaviour "gave rise to a reasonable intention of bias".
"A fair-minded observer might reasonably have apprehended that (Mr Sofronoff) might have been influenced by the views held and publicly expressed by Ms Albrechtsen," he told the ACT Supreme Court.
Justice Kaye's decision did not completely vindicate Mr Drumgold, having upheld seven of the eight inquiry findings the prosecutor disagreed with.
But the report's accusation Mr Drumgold had engaged in "grossly unethical conduct" while cross-examining Senator Linda Reynolds was "legally unreasonable'', Justice Kaye said.
As a result of the decision, the ACT government will cover some of Mr Drumgold's legal costs, though a figure has not yet been determined.
The inquiry was launched after police and prosecutors made claims about each other's conduct during the trial of former political staffer Lehrmann.
Prior to Monday's decision, Mr Drumgold's lawyer Dan O'Gorman told the court of Mr Sofronoff's frequent contact with Albrechtsen.
Between February and July 2023, the inquiry head made 65 phone calls to journalists - 55 of which were to those from The Australian and most of the time was spent with Albrechtsen.
During the public hearing part of the inquiry, Mr Sofronoff made 10 calls to The Australian, eight of which were with Albrechtsen.
Mr Drumgold resigned from his role as the ACT's Director of Public Prosecutions in August after the release of Mr Sofronoff's report.
In 2019, Lehrmann was accused of raping his then-colleague Brittany Higgins inside the Parliament House office of Senator Reynolds.
But his 2022 ACT Supreme Court trial was abandoned because of jury misconduct and a retrial did not proceed over concerns about Ms Higgins' health, leaving no findings against him.
Lehrmann has always denied the allegation.
On Friday, the ACT government apologised and paid former defence minister Linda Reynolds $90,000 after Mr Drumgold accused the senator of "disturbing" conduct in a letter of complaint to the Australian Federal Police that was later published in the media.
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