This involved 4,412 fraud cases of Rs 1 lakh and above, as per the report.
In FY19, banks had reported 6,801 cases of fraud involving Rs 71,543 crore.
"An analysis of the vintage of frauds reported during the FY19 and H1 FY20 shows a significant time-lag between the date of occurrence of a fraud and its detection," RBI's Financial Stability Report said.
The amount involved in frauds that occurred between FY01 and FY18 formed about 90.6 per cent of the frauds reported in 2018-19 in terms of value.
Similarly, 97.3 per cent of the frauds reported in the first half of FY20 by value occurred in previous financial years.
During the first half of 2019-20, banks reported 398 cases of large value frauds (above Rs 50 crore) worth Rs 1.05 lakh crore.
Lenders reported 21 cases of frauds above Rs 1,000 crore, worth a cumulative Rs 44,951 crore.
The report said loan-related frauds continued to dominate in aggregate, constituting 90 per cent of all frauds reported in FY19 by value and 97 per cent of all frauds reported in H1 FY20.
The Reserve Bank is taking steps to integrate fraud reporting of NBFCs and urban co-operative banks in its central fraud registry database.
Such interlinking would serve as an invaluable resource in effective fraud detection/monitoring, it said, adding, "a greater thrust has been put on improved governance."
Special emphasis is being given towards specific expectations on board/ its committees and senior management towards fraud management.
A sharpened focus on fraud response plan is being sought from the banks and for this, stricter timelines and clear cut guidance with respect to reporting of frauds and declaration and processing of red flagged accounts (RFAs) will be prescribed, the report said. HV ABM ABM