Two custody officers at Auckland District Court were injured after being assaulted last Tuesday, police say.
Police said the two employees were escorting a man back to custody from a courtroom when they were attacked without warning.
"The two staff members endeavoured to restrain the man but required the assistance of additional staff, who arrived quickly," Detective Inspector Glenn Baldwin, from Auckland City CIB, said.
He said both officers suffered facial injuries and were taken to hospital in a moderate condition.
Both had since been discharged and were recovering at home.
Police were investigating, and Baldwin said further charges would be laid against a 31-year-old who was in custody over other matters.