People are suffering while on the Southern District Health Board's cancer treatment waiting list

At least 27 people are considered to have suffered harm, with three becoming so sick they became unfit for treatment while waiting.

OIA documents released to the Otago Daily Times show clinicians raised the alarm about unacceptable waiting lists for cancer treatment, in January.

However it took until May for the DHB to approve outsourcing cancer treatment to address the problem.

Cancer Society Otago and Southland division chief executive Rachael Hart says the wait times local people are enduring is an ongoing concern.