A court has released footage from inside the hastily set-up youth justice centre inside Victoria's maximum security prison which shows teenagers being capsicum-sprayed during a disturbance now under investigation.

Emergency response guards from Barwon Prison enter the centre, known as the Grevillea Unit, after one of the inmates tossed two chairs at a staff member.

The situation quickly escalates when one of the guards responds with capsicum spray, affecting everyone in the unit — including juvenile detention staff.

They can be seen accompanying the teenagers into the exercise yard as the guards from the adult prison regrouped and put on masks.

The juvenile detention staff can also be seen counting the boys before being ushered back into the unit from the exercise yard.

Adult prison guards can be heard on the footage describing the teenager's as "little f**ks".

The teenagers are locked out and allegedly went on to damage the yard and adjoining visitor centre.

Later, the guards are accused of restraining and assaulting the teenagers in their cells. Those claims are under police investigation.

The Victorian Supreme Court has released the security vision as it hears a legal challenge to the Victorian Government establishing a youth justice centre inside a maximum security adult prison.

Lawyers representing the teenagers have told the hearing the youth justice centre is not just inside a maximum security adult prison but resembles one.

"A place that retains the attributes of a … maximum security adult prison cannot be a place … that complies with the unique set of rights that children on remand and in detention hold under the act," Dr Ian Freckelton QC told the hearing.

But lawyers representing the State Government denied the youth justice centre is unlawful.

They told the hearing it was the best option for accommodating the teenagers after a riot damaged the Parkville youth justice centre.

The State Government declined to comment on the footage released by the court as the case is ongoing.