Police Commissioner Howard Broad says additional effort will be made to ensure that officers' behaviour is improved.
On Tuesday the Office of the Auditor-General released a progress report on changes made since 2007, when the Commission of Inquiry into Police Conduct made 60 recommendations.
The commission followed rape allegations by Louise Nicholas.
The report says police still have a lot of work to do to ensure that officers' conduct meets appropriate standards. That includes zero tolerance of sexually inappropriate behaviour.
Police are also being told they must do more to ensure that sexual assault victims are treated fairly when they make a complaint.
The report says they could lose any gains they have made unless they make an effort to change their culture.
Making sexual jokes 'risks job loss'
Mr Broad says police are working to improve their monitoring of how well the changes are working. He told Checkpoint that officers risk losing their jobs over inappropriate conduct, such as making sexual jokes.
Police Minister Judith Collins says that while many of the report's recommendations have not been fully implemented there has been a great deal of improvement and progress.
Ms Collins says the culture of a 12,000-person police force cannot be changed overnight.
Andrew McConnell of the Auditor-General's Office says that while progress has been made it is now at a critical point.
He told Checkpoint that, for example, police have to make more effort to ensure that new rules and standards for sexual assault investigations are actually being followed by all officers around the country.
Nicholas concerned but hopeful
Ms Nicholas says she's concerned that only seven of 40 recommendations have been completed but adds that there is a way to go until the end of the process and that she is hopeful there will be change.
She told Morning Report the public are watching the police.
Police Association president Greg O'Connor says it is important any sexually inappropriate behaviour is dealt with quickly.
But he says the focus on police conduct should not overshadow the core business of preventing crime.