"At this stage police have not been able to speak to this couple so will be carrying out a scene examination at the Whakatu address and speaking with people who contacted emergency services regarding this event to begin to establish what happened," he said.
A St John Ambulance spokesperson said they were called to the address after a 111 call.
"They rang and said they needed an ambulance and just hung up."
Mr de Lange told Hawke's Bay Today that police had not yet determined what the woman was doing at the time she was burned.
He said CIB were involved because her injuries had the potential to cause death.