Police were called to reports of a robbery at a residential address on Stanmore Rd in Linwood about 4.42pm on Thursday.
Nothing was taken from the property, but one person was assaulted and received head injuries.
They were treated by St John ambulance staff at the scene following the incident, a police spokeswoman said.
The two offenders were reportedly carrying wooden bats, but the spokeswoman said it was unclear how the person was injured.
A 40-year-old man was arrested and charged with injures with intent on Friday. He is due to appear in the Christchurch District Court.
The spokeswoman said the incident is being investigated and police are trying to locate a second person involved in the incident.
Police were unable to provide any further details about the person's description at this stage.
