The idea that anyone would willingly confess to a crime they didn't commit sounds unbelievable, particularly when the punishment may be life in prison or even the death penalty.

But a series of high-profile cases across America has revealed a slew of wrongful convictions based on false confessions and placed the spotlight on a widely used police interrogation technique designed to make people confess.

It's almost three years since Four Corners exposed shocking revelations of mistreatment in the Northern Territory's Don Dale youth detention centre in Australia's Shame, sparking a Royal Commission.

Now the program is set to reveal a new child detention crisis in another part of Australia, where children as young as 10 have been held alongside adult criminals in maximum security facilities.

With exclusive access, the program goes behind the locked cell doors to reveal how young people, most of whom have not yet been convicted of a crime, are being held, sometimes for weeks at a time.