The Reserve Bank is looking closely at bank funding costs to ascertain whether rate rises are justified.
As reported in the Australian Financial Review, the RBA is currently interviewing senior executives from the big banks as it prepares to release a report into bank funding costs next month.
The Australian Bankers' Association has welcomed the RBA's independent scrutiny.
Australia's largest banks have been questioned after their decision to raise rates despite the RBA's decision to remain pegged at a benchmark cash rate of 4.25%.