The NSW police commissioner insists a decision not to publicly disclose a senior colleague's serious drink-driving charges was not a cover-up but something that "slipped through the cracks".
The high-ranking detective had allegedly been drinking at a function before getting behind the wheel of his police-issued car in May.
The 46-year-old later allegedly crashed the vehicle in the early hours of the morning, before reportedly leaving it in a street in Sydney's north.
Commissioner Karen Webb on Wednesday said she had been aware of the incident since May but there had been a "lengthy and comprehensive investigation" before officers had put their case to the Director of Public Prosecutions.
The off-duty officer was subsequently accused of driving with a blood alcohol level of more than 0.15, or more than three times the legal limit.
He was charged on Friday with high-range drink-driving, an offence that carries a maximum jail term of 18 months, and driving under the influence.
Ms Webb told Sydney radio 2GB the officer was not subjected to an oral or blood test on the night of the crash and investigators would be "relying on any other evidence they've got available to them" in making the case.
When asked why NSW Police did not issue a public statement on the charges, as is routinely done when an officer is accused of a crime, she said the matter "fell through the cracks".
Ms Webb denied the officer had in any way been "protected", despite the six-month delay in prosecution while police waited for DPP advice.
She said that process was not unusual as they prosecuted matters involving officers.
"We had to wait for the legal process to take its course and I can't make that go any quicker," she said.
"Any suggestion that there's a cover-up or interference, I reject."
The decision not to disclose the officer's charges was not based on advice from the Crown Solicitor's Office, which was separately considering whether to ask the court for a suppression order on the case, Ms Webb said.
The commissioner has referred the matter to both the internal Professional Standards Command and the independent watchdog, the Law Enforcement Conduct Commission.
The officer's employment status is under review.
Deputy Commissioner David Hudson said in his opinion a statement should have been issued about the charges, noting that decision would form part of the watchdog's review.
He said due to "a certain classification of this officer", access to the case details were restricted and he did not believe the police media unit knew.
The officer will face Hornsby Local Court on December 21.