New South Wales police are promising to dismantle their despised promotions system, end the force’s “boys club” culture, and clamp down on sexual harassment in a bid to level the playing field for female officers.

The police union is calling for urgent action, noting the “disturbing” findings of a new report have not come as a shock to everybody.

In June last year, former Australian sex discrimination commissioner, Elizabeth Broderick, was tasked with examining the impact the police force’s internal culture is having on women trying to move up through the ranks.

The review, released on Sunday, surveyed almost 3,500 officers online and sat down with focus groups and individuals. It concluded women were forced to conform to a “masculine culture” to find a position in the organisation.

“Female police officers conveyed to the review that they have to modify their behaviours and are constantly trying to ‘prove themselves’ in order to be ‘accepted’ and ‘taken seriously’.”

Further, the report found two-thirds of female officers felt cliques, in-crowds and the “boys club” formed a barrier to promotion. Over half of male officers also felt excluded from the informal networks in the force.

One in three women reported being sexually harassed by a colleague in the last five years, the review says, while only 13% men said the same.

Only 15% of officers said they had make a formal complaint fearing it could negatively impact their career.

NSW police moved towards a new promotions system designed to combat corruption and nepotism in the early 2000s.

But now that system evokes “almost universal dissatisfaction” from police because it’s seen as too rigid, onerous, slow-moving, affected by cliques and indifferent to carers, the review says.

“There is a general view that the promotions system as it currently operates does not always ensure that the best candidate is promoted,” it says.

The force does not appear discriminatory on the surface, police told the review, but the fact women are more likely to be carers means they’re facing disproportionate adversity.

“Loss of standing due to working part-time creates a cascading effect where women are less likely to be given ‘the big jobs’ which can impact on their opportunities to further progress.”

As a result female officers are under-represented in all leadership positions.

The commissioner, Mick Fuller, who requested the review, welcomed the findings and fully supported the 30 recommendations it made.

He pledged to move past the “male-dominated bygone era” and bring in a new, equitable promotions system.

“A police officer, male or female, who is trying to balance family and home life with their careers, through part-time and flexible working arrangements, should not be discriminated against or overlooked for promotion and development,” he said in a statement on Sunday.

The president of the Police Association of NSW, Tony King, said the findings were “confronting”.

“Unfortunately for those of us who have been calling for reform for a long time, they haven’t come as a complete shock though,” he said in a statement on Sunday. He called for a high-quality complaints system to address harassment.

“The statistics around the number of police being sexually harassed at work is unacceptable – that simply cannot go on,” he said.

He applauded Fuller for addressing the serious issues in the force.