Banks have been found to be breaking rules set for them by regulators when dealing with mortgage holders who are in arrears.
A new Central Bank probe found some banks are continuing with legal actions to repossess homes even though a revised payment deal had been agreed with the struggling homeowner.
Other banks were taking away Central Bank protections for mortgage customers because they did not agree to a repayments schedule over the telephone.
This is despite the fact that banks are required to communicate a revised payment arrangement in writing, the Central Bank said. Seven banks were inspected.
None of the rule-breaking banks were named, but they were warned that regulators would be taking actions to force them to observe the rules for dealing with vulnerable homeowners in arrears.
The themed inspections found evidence that lenders were changing standard financial statements submitted by mortgage holders without referring back to the borrowers.
There are strict rules setting out how banks are to deal with people in mortgage arrears, known as the Code of Conduct on Mortgage Arrears.
And the inspections of the lenders found that some banks were seeking irregular payments from stricken mortgage holders, on top of agreed revised payments.
There are 105,000 residential mortgage accounts in some form of arrears.
The Central Bank said in a statement: "We also identified cases where lenders continued to call borrowers directly and/or did not liaise with third parties, even though borrowers had formally nominated these persons to act on their behalf."
Central Bank inspectors found that banks were not keeping to time frames for dealing with distressed borrowers.
Meanwhile Finance Minister Michael Noonan has again signalled that a bank levy may happen if the banks do not reduce variable mortgage interest rates.
The minister said he will review progress with the banks before the Budget in October and meet the banks next in September.
"There is obviously an advantage for banks to move to fixed rate mortgages, because they can fund against the fixed rate at a lower rate than they would against variable rates on the market," he said.
Banks have until July 1 to present the minister will proposals for reducing the burden on variable mortgage holders.