The Central Bank has written to lenders requesting information and copies of confidentiality agreements made with mortgage holders whose loans have been restructured.
In a letter to Finance Committee chairman Ciaran Lynch, the Central Bank said that while restricting such agreements would go beyond its powers it would assess the matter when it received information from lenders.
Mr Lynch had written to the Central Bank expressing his concerns about such agreements.
The Central Bank also said it is also considering whether to require lenders to provide more information to consumers about such agreements as part of the revised Code of Conduct on Mortgage Arrears, due to be published this week.
When the various lenders were asked if they require confidentiality agreements in connection with restructuring deals with mortgage holders, Bank of Ireland and IBRC would not comment.
AIB/EBS said non-disclosure agreements are not used for basic mortgage arrears cases.
They said they are used on a case-by-case basis, typically in a wider business context or for larger property investment debts.
Permanent TSB and Ulster said they do not require them.