He was 82.
Dr Williams, a distinguished medical practitioner in Auckland, was admitted to hospital after testing positive for Covid-19 on August 13.
His medical practice was near the Americold cold store at the centre of the new community-transmission virus cluster in New Zealand.
Dr Williams served briefly as prime minister in 1999.
Cook Islands News extends deepest condolences to Dr Williams’ family at this sad time.
*More in tomorrow’s edition.