A ban on encrypted messaging apps and social media on police-issued devices has been labelled a blow to the force that could harm officer retention.
NSW Police said on Monday it had introduced security software that would prevent the apps from being downloaded and from functioning on official-issue devices.
The measure stemmed from an investigation into allegations of a cover-up over a senior officer's car crash while allegedly drink-driving in Sydney's NorthConnex tunnel in 2023.
The state's Law Enforcement Conduct Commission uncovered evidence some police had "adopted the practice of deleting messages, records of messages and calls from encrypted applications".
The watchdog urged NSW Police to consider whether the practice of automatically deleting electronic messages was consistent with official policy on keeping records and to issue guidance on use of encrypted apps on work phones.
Opposition police spokesman Paul Toole said the ban was "another blow to make a difficult job even harder" and would have officers consider their futures due to the extra scrutiny.
"We need to be backing our police for the job they do, not impeding on their communication with fellow officers and avenues of tracing criminals through social media," he said.
"Banning them from using certain apps means many will just find another way to do so, including resorting to carrying two or more devices."
The watchdog's investigation found the senior officer involved guilty of serious misconduct, but stopped short of finding other police enacted a cover-up plot by failing to publicly declare the incident.
Following the probe, NSW Police Commissioner Karen Webb referred concerns officers were using encrypted messaging services to the force's Public Affairs Branch.
NSW Police said its Professional Standards Command was "also currently reviewing other LECC positions and opinions from that same report".
The watchdog found the senior officer who crashed the car had consumed almost 24 standard drinks but was not charged with high-range drink driving until nearly six months later.
Police did not issue a public statement about the allegations until media reported them, prompting suggestions there was a desire among the force's leadership to cover up the events.
The commission found no evidence the lack of public disclosure involved impropriety, while noting it had hurt the reputation of the force.
The officer, whose identity has been suppressed, has been charged and remains before the courts.
The Police Association of NSW declined to comment on the encrypted-messaging move.