The case is that of 48-year-old woman who died from cancer and whose illness, authorities say, may have been complicated by Covid-19.
She was admitted to ward 2A on July 7 and died on July 13 at the Port Moresby General Hospital.
Hospital chief executive Dr Paki Molumi told NBC News that the scale-down was on non-essential services, like elective surgery, the consultation clinic and outpatients.
Molumi confirmed that essential services, such as the emergency department, children's outpatients, labour and maternity wards would remain open.
''The scale down exercise is done to free up some staff to do surveillance and contact tracing on all the staff that has come in contact with the patient,'' Molumi said.
Meanwhile, decontamination is being carried out on the whole hospital, starting with the Ward 2A of the hospital where the case was admitted to.