The Northern Territory’s royal commission into child protection and detention says no more vulnerable children will give evidence before the inquiry wraps up for the year.

The inquiry earlier flagged it would hear testimony from at least 12 in the December hearings, but only two have so far given evidence before the final day on Wednesday.

One took the stand anonymously and the other was Dylan Voller, the teen inmate who was notoriously tear gassed, shackled and put in a spit hood in events that sparked the commission.

It comes after the longtime caseworker for Dylan Voller said he was “set up to fail” from the start by the system.

Antoinette Carroll, Voller’s youth justice advocate for seven years, told the inquiry on Tuesday the now 19-year-old had been put on a destructive “merry go round” of reoffending.

Ms Carrol says it is because the justice and protection system had failed the boy from a young age by neglecting diversionary programs and adopting a punitive approach.

Ms Carroll also said Voller’s detention had turned him violent, denied him rehabilitation and failed to help him re-enter society.