A sworn member of ACT Policing who republished a nude female photograph from the agency's official Twitter account breached professional standards, an internal investigation found.
But the former employee, who was believed to have held a senior role with the organisation, escaped formal punishment because they had already resigned.
The resignation was not related to the embarrasing social media mishap, which attracted national media coverage, the Australian Federal Police said this week.
The offending tweet was published from an account named Katie Sanders and retweeted from the official ACT Policing account to thousands of followers on December 31 last year.
The message included three naked photographs of a woman wearing only boots and read "One good thing about winter..these boots!".
The message featured the hashtag #ThonglessThursday and was originally posted 18 days before ACT Policing republished it.
The explicit image was deleted from the official police account minutes after it was shared and ACT Policing stopped following the woman's account about 20 minutes later.
Several of Ms Sanders' pornographic tweets, which had been added to the accounts' favourites as far back as early December, were also "unfavourited" that same day.
Police said in January an internal probe had been launched to find out how the image came to be retweeted.
Chief Police Officer Rudi Lammers said at the time the staff member confessed to the AFP professional standards unit immediately after the incident.
He said the staffer was not a member of the force's dedicated media unit, which generally looks after the force's official social media accounts.
An initial investigation wrapped up in February and a report was given to the employee for right of reply, before it went back to the adjudicator for a decision.
That investigation was completed this month and the AFP's professional standards unit found two breaches of the agency's code of conduct.
The AFP this week said "no sanction applied" because the person had resigned for reasons unrelated to the incident before the matter was finalised.
A spokesman said misconduct matters within the AFP were usually addressed through a range of methods from counselling, warnings, increased supervision and training, to criminal charges and sacking.
The AFP has refused to be drawn on the category or seriousness of the breaches but said the former employee had been told of the outcome.
It would not be releasing the name or position of the former employee for privacy reasons.
An internal report into the incident would not be made public.
ACT Policing reviewed its social media protocols after the incident.
It prompted territory police chief Rudi Lammers to reinforce his "very high expectation" of all senior staff to model good behaviour across all facets of the job.
"The higher you are in the organisation the greater the level of responsibility and adherence to standards that you must have because you not only follow the standards but you model them."
AFP Commissioner Andrew Colvin earlier this month warned police officers they should be "acutely aware" their actions could be filmed and shared on social media, following a string of incidents that drew public criticism.
Indigenous broadcaster NITV lodged a formal complaint against the Australian Federal Police after journalist Myles Morgan claimed he was intimidated by officers while filming a scuffle between police and participants in a march in Canberra on Anzac Day.
Last year an ACT Policing officer was found to have breached professional standards after CCTV footage showed him using capsicum spray towards a tethered dog during a property search.
