The Central Bank says around 13,000 accounts have been impacted by the tracker mortgage scandal - an increase of 3,100 compared to the financial regulator's last report in March.
Tracker mortgages are set at a fixed percentage or 'margin' above the European Central Bank rate.
However, a probe revealed that thousands of customers of several Irish lenders were overcharged or wrongly denied a tracker rate
In their latest report on the situation, the Central Bank explains: "Approximately 60% of impacted accounts arise as a result of customers not receiving tracker products and approximately 40% of impacted accounts arise from customers not receiving correct tracker margins."
Lenders are also said to be analysing situations where people lost ownership of property due to the issues with the tracker mortgages.
Current figures show that 23 private homes and 79 buy to let properties were lost as a result of the errors - but the financial regulator is warning this figure will rise as lenders continue to analyse their data.
So far, €120 million in compensation has been provided to around 3,300 affected customers - in addition to redress & compensation from Permanent TSB (€36.8 million) and Springboard Mortgages (€6.2 million).
The report notes: "The Central Bank expects that all lenders will have commenced providing redress and compensation to customers identified by lenders as impacted to date by year-end.
"The Central Bank will rigorously pursue its enforcement investigations. "
However, it also warns: "The Central Bank is concerned that two lenders may have failed to identify populations of impacted customer or failed to recognise that certain customers have been impacted by their failures.
"The Central Bank is of the view that certain of these customers are in fact impacted and accordingly entitled to redress and compensation."
Those two lenders are said to be conducting fresh reviews, and are due to report to the Central Bank by the end of the month.
Last week, some of the tracker mortgage holders affected told the Oireachtas of the devastating medical and financial effects on their families.