Senior medical staff at the then National Women's Hospital approved the study, eventually found to have been unethical during an inquiry by Dame Silvia Cartwright in 1987-88.
Her inquiry uncovered a failure to treat the early stages of cervical cancer for patients in the study and also failed in doctors' ethical practices in relation to information sharing and obtaining informed consent.
In a written statement some 50 years later, the DHB admitted the experiment run by Professor Herbert Green in the 1960s and 70s led to early deaths.
Sandra Coney, who with Phillida Bunkle wrote the Unfortunate Experiment story in Metro magazine, said Matheson was a "courageous and strong woman" who was essential in exposing what had happened.
"And who kept speaking up even when in the hospice. I am grateful to have known such an inspiring person as Clare."
The Unfortunate Experiment article resulted in the Cartwright Inquiry which confirmed the allegations made in the story.
Former MP Judith Tizard said she, like most New Zealand woman, knew about Matheson through the Unfortunate Experiment.
"I met Clare when she was supporting another woman. I was impressed by her breadth and generosity.
"She had serious health problems, I am only alive today because of the cervical screening programme that was instituted following Silvia Cartwright's report and Helen Clark as Minister of Health putting in the cervical screening system."
"I am one of the thousands of New Zealand woman alive today because Clare spoke up and Sandra and Phillida did that work.
Matheson was very involved in creative areas, specifically in West Auckland, Tizard said.
"Like many people who have been through a life-threatening experience, we realise there is a bit more to life than our own."
