A legal case brought against Northern Territory Police by one of their most experienced detectives has been dropped, but that has not quelled disquiet about a broader "purge" of experienced investigators.

Key points: Experienced detectives moved out of Major Crimes Unit to traffic duties

Experienced detectives moved out of Major Crimes Unit to traffic duties Fears "reshuffle" may undermine quality of police investigations

Fears "reshuffle" may undermine quality of police investigations NT Police acknowledges "staff movements" over recent months

Sergeant Isobel Cummins was suing NT Police after being quietly moved out of the Major Crimes Unit, along with several other detectives.

The detectives were among some of the most experienced investigators in the Territory, but one was transferred to traffic duties, while another has been riding Segways around Darwin's CBD dealing with anti-social behaviour.

"This was undeniably a purge of some of our best investigators," said one senior police officer, speaking on the condition of anonymity.

That officer said the staff changes came after an internal police investigation into suspected rorting of overtime cleared the officers of any wrongdoing.

"It's like something written by George Orwell, where they ran an investigation that didn't get the results they wanted, and then just moved people they didn't like out anyway," the officer said.

But another source familiar with situation said there were claims the staff changes were only designed to achieve "cultural change" within the elite investigative branches.

Both sources agreed the unit had become factionalised, with young detectives eyeing off promotions and looking for ways to get rid of the older, more experienced officers.

Sergeant Cummins alleged she was denied procedural fairness in a writ filed in the NT Supreme Court.

That civil case has now been resolved, but neither NT Police nor Sergeant Cummins would say what agreement had been reached, or whether she or the other officers had been reinstated in the Major Crimes Unit.

Concerns reshuffle will lead to 'bungled' investigations

Northern Territory Police declined an interview.

"The Northern Territory Police Force has many experienced detectives," Acting Assistant Commissioner Kristopher Evans said in a statement.

"There have been staff movements within Crime Command over recent months.

Mr Aust has raised concerns about the standard of investigations following the exodus of senior detectives. ( ABC News: Bridget Judd )

"NT Police is committed to, and will continue delivering, a high quality investigative service to community of the Northern Territory, whilst acknowledging the recent commentary from the coroner."

Northern Territory Police have been under pressure after the coroner pilloried their "bungled" investigation into the death of Indigenous woman Sasha Green.

The coroner said it appeared police had not learned from similar mistakes made after the 2007 death of a young Indigenous boy.

"The standard of justice for victims, witnesses and alleged perpetrators is simply not up to scratch in the Northern Territory," the Criminal Lawyers Association of the Northern Territory president Marty Aust said.

Mr Aust said he "absolutely" had concerns about the standard of investigations in matters such as homicides and sexual assaults now that senior detectives had been moved out.

But he also raised concerns about the quality of investigation in less serious offences which did not attract the same level of scrutiny.

"People charged with offences spend weeks and months of their life in custody because of strict bail laws and then they're released because the investigation simply doesn't come up to scratch," he said.

"These issues mean that everybody who's represented in the criminal justice system, including the victims, witnesses, people who have an interest in justice being fulfilled, are losing out."