To a query under the Right to Information (RTI) Act, the Reserve Bank of India (RBI) said the process of destruction of banned notes got over in March 2018.
In its reply dated October 29 to the query by Chandrashekhar Gaud, an RTI activist from Neemuch in Madhya Pradesh, the RBI said invalidated notes worth Rs 10,720 crore did not return to the banking system.
The information was provided by the RBI's Department of Currency Management, Gaud told PTI.
The banned currency was destroyed through machines of the currency verification and processing system, it said.
To Gaud's question about how much the destruction of banned currency cost, the reply gave no information.
It cited Section 7(9) of the Right to Information Act, saying this information was not available and providing it would "disproportionately divert the resources" of the RBI.
Currency worth Rs 15,41,793 crore in denominations of Rs 500 and Rs 1,000 was in circulation when demonetisation was announced on November 8, 2016. In the time window offered for depositing the scrapped currency in banks, Rs 15,31,073 crore returned, it said.
Gaud said he also did not get a reply to his query as to how many Rs 500 and Rs 1,000 notes were destroyed.
The RBI had informed in August this year that as much as 99.3 per cent of the junked Rs 500 and Rs 1,000 notes returned to the banking system.