The ACT’s chief police officer has signalled he wants the planned public inquiry into Bruce Lehrmann’s rape trial to examine the behaviour of Director of Public Prosecutions Shane Drumgold SC and an alleged contempt of court by Brittany Higgins, as the rift ­between Territory police and the DPP spirals into crisis.

Allegations of misconduct around the case have been ­referred to the Australian Law ­Enforcement Integrity Commission following publication of a ­letter of complaint sent by Mr Drumgold to police chief Neil Gaughan alleging “inappropriate interference” by police during the investigation and trial.

In the letter released by the DPP under Freedom of Information laws to The Guardian but withheld from other media outlets, Mr Drumgold said there was “a very clear campaign” by police to pressure him not to prosecute Mr Lehrmann for the alleged rape of Ms Higgins.

Mr Drumgold called for a public inquiry to examine “both political and police conduct”, but on Friday Deputy Commissioner Gaughan made it clear police also wanted the prosecution’s conduct firmly in the inquiry’s sights.

In an email to his officers, Commissioner Gaughan welcomed a public inquiry “into all aspects of the matter including … the actions of police, the prosecution and ­defence, issues leading to delays in the trial, issues leading to the subsequent mistrial, the decision not to proceed and the associated ­allegations of contempt of court”.

Ms Higgins’ statement outside court after the trial was aborted, comparing her treatment with the accused’s right to silence, were ­referred by the defence to police for possible contempt of court.

Mr Lehrmann has indicated he may sue the ABC for broadcasting the comments. Commissioner Gaughan acknowledged “the dedication, professionalism and commitment” of the officers ­involved in the investigation. He also noted that ACT Policing had not been consulted by the DPP in the FOI process, a failure that the police union says is potentially in breach of the law.

The ACT’s Freedom of Information Act states that the “respondent must take reasonable steps to consult with the relevant third party before deciding to give ­access to the information”.

The release of the letter to The Guardian comes after revelations by The Australian that police ­believed there was in­sufficient evidence to prosecute Mr Lehrmann but could not stop the DPP from doing so because, in the words of one senior investigator, “there is too much political ­interference”.

The DPP has refused to provide a copy of Mr Drumgold’s letter to The Australian and several other media organisations, or to provide an explanation for withholding it, saying only that the document would be released on Monday.

The DPP also declined to comment on moves by the police union to refer the release of the letter to the Office of the Australian Information Commission and the ACT Ombudsman as a possible breach of FOI laws.

Australian Federal Police ­Association president Alex ­Caruana said the unredacted letter included personal details of officers involved in the investigation.

He slammed Mr Drumgold for failing to report allegations of ­inappropriate conduct by police to the ALEIC when he became aware of it, rather than months later. The inquiry must also assess the conduct of ACT Victims of Crime Commissioner Heidi Yates and Attorney-General Shane Rattenbury, he said.

Mr Lehrmann pleaded not guilty at a trial in Canberra that was aborted as a result of juror misconduct. He has repeatedly stated his innocence.

EDITORIAL P12

INQUIRER P19