People who care for the elderly say it is family members who are responsible for most of the abuse or neglect of old people, but only one case in six is ever reported.
Age Concern says more than 1000 cases are referred each year, but several thousand more involving psychological, financial or physical abuse or neglect are kept hidden.
The agency says about four abuse cases a day are reported in New Zealand.
Its Nelson manager, Sue Tilby, says most abusers are sons and daughters or grandchildren.
Ms Tilby says family members often manipulate parents over money, sometimes draining their bank accounts, and the abuse often continues when they move from the family home into specialist care.
Many cases of abuse are not reported because the victim fears the repercussions of speaking up, she says.
Wednesday is Elder Abuse Awareness Day and people who are aware of abuse cases are urged to seek advice and help from social agency experts.
