THE Central Bank has been urged to carry out a full probe after more cases emerged where people have had their tracker mortgages restored.
Consumer advocate Brendan Burgess said there were thousands of homeowners who lost trackers but should have got them back.
Mr Burgess said the regulators should intervene to ensure that people entitled to a good-value tracker get to keep it.
He said that people who complained to the ombudsman or got help from a broker were getting their trackers back.
But individuals who attempted to be put back on a tracker were less successful, the founder of askaboutmoney.com said.
His call came as a new batch of homeowners have succeeded in getting restored to trackers at Ulster Bank and AIB.
Tracker rates are tied to the European Central Bank base rate and can only change when it moves. Trackers are typically set at 1pc above the ECB rate, making them the cheapest mortgages in the market.
One broker said he had secured €300,000 in compensation over a bank's failure to put people back on trackers when they finished on fixed rates.
For the AIB, Bank of Ireland and Permanent TSB, homeowners had opted to move from trackers to fixed rates, but the banks had failed to outline in letters at the end of the fixed period that the customers had the option of going back.
Central Bank rules also force banks to warn customers of the cost implications of coming off a tracker to move to a fixed rate or a variable rate.
Asked if it had any plans to probe lenders, the Central Bank would only say that lenders are required to make very clear to mortgage holders the implications of moving off a tracker.