Union 'deeply concerned' after prison guard injured at Canberra's Alexander Maconochie Centre

Authorities have been reluctant to release more information about the "incident" at the jail on January 15.

However it is understood three prison guards were hurt while trying to restrain an inmate.

"The incident was quickly responded to and contained through normal response actions," a spokesman for the ACT's justice directorate said.

"All persons involved in the incident, including staff, have received support and medical treatment as required."

The spokesman said that, as police were now investigating the scuffle, it would be inappropriate to comment further.

However Community and Public Sector Union ACT regional secretary Vince McDevitt said he would press prison authorities for more information on how the injuries occurred.

"We are deeply concerned that a prison officer has been injured while going about their work and will be seeking a full briefing from prison management," Mr McDevitt said.

ACT Policing said no charges had yet been laid but could not comment further due to privacy constraints.

It is not the first time guards have been injured by inmates at Canberra's jail.

In 2014, murderer Aleksander Vojneski bashed a guard who told him to fill out a prisoner complaint form after he complained someone had forged his name to buy groceries.