Vulnerable eldery people having money and property taken off them by preying family members are a major cause for concern, according to the Age Action group.
Demands for cash, access to bank accounts and even putting people out of their property have been reported in a survey carried out by the charity and Ulster Bank.
Research has found that almost half of bank officials have dealt with elder financial abuse situations through their work.
In one case, the charity dealt with a woman in her late 70s who was left in sheltered accommodation after her son moved into her home and later refused her access.
Another case focussed on the story of a woman who was diagnosed with dementia.
During a period when she was experiencing reduced mental capacity, her son persuaded her to set up a joint bank account.
He then used this account to get a credit card from a bank and made a number of purchases on it for which his mother was charged.
During a more lucid period the woman realised what had happened, and with the help of her daughter she approached her bank which recognised the transactions as fraud and reimbursed her.
"Every year, hundreds of older people face demands for money from family members, having their income withheld from them or finding their possessions taken," said Justin Moran, head of advocacy and communications at Age Action.
"To make it worse, in the overwhelming majority of cases of elder abuse, the perpetrators are immediate family members," he added.
"This abuse may happen in a very subtle way. Often an older person might be made feel they have some obligation to give money to a relative ar grant them access to their bank account," said Mr Moran.
The survey asked 493 Ulster bank customer service staff about their experience of elder financial abuse.
It found 45pc of respondents had dealt with suspected elder financial abuse cases, almost all of whom had dealt with at least one case in the previous year.
Almost 70pc of the bank's respondents were familiar with elder financial abuse, rising to 75pc among those with 10 years or more experience.
There were more than 13,000 cases of elder abuse referred to the HSE up to the end of 2013.
The HSE operates an information line for reporting cases of suspected elder abuse from Monday to Saturday, 8am to 8pm, at 1850 24 1850.
Age Action also runs an information line for anyone who might be concerned about elder abuse. It operates from Monday to Friday, 9am to 5pm, at 01 475 6989.