The stroke victim, who the Herald has chosen not to name, is partly paralysed, incontinent and receiving treatment for a rare terminal cancer.
Burke said she was disgusted to empty out a "full" pair of tracksuit bottoms, which showed he wasn't being changed enough.
"They were absolutely full and untouchable. They hadn't even rinsed it out or disposed of it in the toilet. That explained why my ex-husband rang me up so distressed the other night. There was no way I could put that through the washing machine and I believe he was neglected."
Burke said it was the final straw and after contacting her lawyer she would tell the hospital she won't be washing his clothes anymore.
An invoice would be sent for her costs to be reimbursed.
She said she couldn't afford this on a pension.
"The $42 doesn't include the cost of disinfectant, washing powder, travel and my time. The hospital should be doing his laundry. He is a patient and my barrister says it's a publicly funded system and I shouldn't have to do it."
She claimed family members of stroke patients were being told to do the cleaning because of cuts by the Canterbury District Health Board to reduce its deficit.
"It's definitely cost-cutting by the CDHB and also the gross understaffing of the ward, where they do not have enough nurses to ensure the care of the patients," she said.
Burke said the only response she's got so far from the CDHB was that some financial consideration should be given to her.
"I'm just on the pension and it's through the kindness of my heart [that I'm doing this] because my ex-husband has no friends, no visitors, nothing and his [family] in another part of New Zealand won't pay one cent to his care."
Burke is worried that she's being exposed to toxic traces from his chemotherapy and an antibiotic-resistant bug.
Canterbury DHB says laundering services for patient clothing are not provided in Older Persons Health wards at Burwood Hospital.
"In the event of a patient experiencing incontinence and when their clothing is soiled, staff will rinse the clothing and ensure it is appropriately bagged for family to take home.
"Should there be any precautions required in relation to infection prevention and control, staff will ensure the family have received information and commit to following advice about how to manage this - for example, laundering separately from other clothing," said general manager older persons health & rehabilitation services Kate Lopez.