The conduct of a former judge who presided over an inquiry into the criminal prosecution of Bruce Lehrmann will be investigated by the ACT’s corruption watchdog.

The ACT Integrity Commission confirmed on Monday it would launch a probe into the conduct of Walter Sofronoff KC, saying it “may constitute corrupt conduct”.

The allegations relate to Mr Sofronoff’s dealings with journalists during a 2023 board of inquiry hearing and his decision to release the final report to two journalists before it was handed over to ACT Chief Minister Andrew Barr.

“The commissioner has completed his assessment of these allegations and has decided to commence an investigation into the impugned conduct as he suspects, on reasonable grounds, that Mr Sofronoff’s conduct may constitute corrupt conduct,” the integrity commission said in a statement.

“As the investigation is ongoing, the commission will not be making any further public comments at this time.”

The inquiry was set up to examine the handling of the criminal prosecution of Bruce Lehrmann, who was accused of raping Brittany Higgins in Parliament House in 2019.

Lehrmann had denied the allegations, and his 2022 criminal trial was abandoned due to jury misconduct.

A retrial was called off over concerns about Ms Higgins’ health.

In April, a Federal Court judge found during a defamation hearing that on the balance of probabilities that Lehrmann raped Ms Higgins.

A board of inquiry, chaired by Mr Sofronoff, was set up to examine the prosecution of the original criminal trial, leading to ACT top prosecutor Shane Drumgold resigning after damning findings were made against him.

Mr Sofronoff’s final report found the ex-director of public prosecutions had engaged in unethical conduct during the Lehrmann trial.

Mr Drumgold launched legal action last August to invalidate the adverse findings, with his lawyers arguing MrSofronoff’s communications with Janet Albrechtsen, a columnist at The Australian, had “infected” him with bias.

The ACT Supreme Court was told Ms Albrechtsen had written a number of articles critical of Mr Drumgold.

Acting Justice Stephen Kaye in April found Mr Sofronoff’s behaviour “gave rise to a reasonable intention of bias”.

Mr Drumgold later said he was “delighted” with the ruling and looked forward to moving on after resigning.