Questions are being asked about the effectiveness of the upcoming youth detention review, with revelations two workers have been told they will not be needed to give evidence.

Attorney-General Yvette D'Ath ordered a review into the Townsville and Brisbane youth detention centres after allegations of mistreatment and abuse.

Its terms of reference  focus in particular on incidents already highlighted in the media over the last year.

But the ABC says it has seen statements from two workers who were told they will not be included, even though they have information about the use of excessive force and mistreatment in incidents that have not be reported publicly.

“They don't want to look at what's happening behind the scenes; what's really happening on the floor that creates the issues in the first place,” one worker told reporters on condition of anonymity.

“Why do the kids do what they do? That's what we want them to address.

“The place [Cleveland Youth Detention Centre] is getting worse; it's evidence based they're not doing the right thing otherwise they wouldn't be having the problems they're having.

“They need much more emphasis on de-escalation.”

Australian Lawyers for Human Rights president Benedict Coyne said the inquiry will be too narrow.

“What it seems to be doing is honing in on a couple of incidents and not really properly exploring whether there is a more systemic issue here,” he said.

“The evidence that I've seen, suggests that there is a much more widespread, much more systemic issue of abuse in the youth detention system and the Government should properly make sure the investigation occurs and widens the terms of reference while the inquiry is still ongoing.”

Mr Coyne said any new whistleblowers not included in earlier reviews were not afforded immunity.

“The Government should properly make sure the investigation occurs and widens the terms of reference while the inquiry is still ongoing.”

Opposition spokesman Ian Walker wants a review of the Terms of Reference.

“We've had a riot at the Cleveland Youth Detention Centre last week, we've had significant allegations about behaviour within youth detention centres, we simply have to get to the bottom of this,” he said.

“If there is any problems with the terms of reference, if anyone is being turned away, then the Attorney-General simply has to change those terms of reference.”

The committee in charge of the review is expected to report to the Attorney-General on its progress by the end of the month and is yet to announce hearing dates.

ABC News made enquiries with the Attorney-General's office but was referred to the review committee which is yet to provide a statement.