Police have tightened their use of wanted posts on social media amid accusations they are public humiliation akin to parading people in the stocks.

A police staffer conceded some mug shots of distinctive offenders are a magnet for mocking comments, according to internal documents written in the same year a petition attracted thousands of signatures to stop the "facilitation of bullying on (police) social media platforms".

The police internal presentation, obtained under the Official Information Act, shows a police staffer acknowledging a 2019 public mug shot of tattooed Northland man Reuben Riddell, which was widely scorned, was a magnet for abuse.

Though its use was within policy, "clearly this was going to generate a lot of mocking of the guy," the presentation said.

Digital marketing and communications consultant Anna Rawhiti-Connell said police's practice of posting wanted criminals was outdated, comparing the public humiliation to locking people in the stocks in the town square.

"We don't practice vigilante justice in this country, we have the right systems and processes in place for dealing with crimes and criminals," she said. "I'm not sure we need to go around parading criminals."

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Her previous criticisms of police social media posts as "cutesy", sanitised, content in danger of appearing glib prompted at least one police staffer to raise the issue for discussion at a national summit, according to an internal email. 

"While it's a tad harsh there are some really valid points," the email said.

In 2019 police deleted Facebook and Instagram posts detailing the arrest of three Auckland teenagers after flak from Children's Commissioner Andrew Becroft, who said it was inappropriate and could be a breach of their privacy. 

They also apologised for a tweet praising an officer who ran a World War II-era internment camp for Japanese women and children. 

Rawhiti-Connell said police social media had improved, with more helpful and operationally focussed content, but remained concerned about posting pictures of wanted criminals.

Because Facebook didn't allow organisations the ability to disable comments, the result was often "every man and his dog piling in to make a joke".

"I've very rarely found there to be a scenario in Facebook comments over the course of my career where anything good has come out of them."

Police marketing manager Paul Halford said they had updated processes to "enhance the sign-off for wanted posts".

Police did not post mug shots, nor avoid posting them, on the basis of ethnicity, gender or hair colour, Halford said.

"Police's social media policy... is very clear: 'the person wanted should be considered a risk to staff or the public and apprehending them is a matter of urgency'.

"The policy also states that consideration must be given to the likelihood of the photograph encouraging trolling, however the primary focus is apprehending these people to maintain the safety of the public and staff."

Police had strengthened a profanity filter on Facebook to block phrases, words or commentary contravening policy and guidelines.

Police once paid $10,000 for a social media audit which recommended they dial up the proportion of posts focussed on operational police work, rather than puppy pictures.

Last year Auckland University of Technology marketing lecturer Marian Makkar warned police risked undermining their messaging with inauthentic "fluff" posts.