"I think this must be the slowest exercise by the RBI. But I would compliment the RBI, the RBI is not so slow, unless it is deliberately slow," Congress spokesperson Abhishek Singhvi told reporters.
He asked why the RBI took the "longest time of 10 months" to count the junked Rs 1,000 and Rs 500 notes.
"Every parameter is changed every day. You are now told that the objective of demonetisation was not to prevent money getting back to the banks...," he said.
Singhvi said there was only a marginal increase in spotting of counterfeit currency.
"Why is the return (of old notes) to the banks far less than Rs 5 lakh crore, as was claimed? 99 pc has come back. And if the objective was to have a credit card economy, I am sorry it takes a long time, a lot of infrastructure to create a credit card economy, not the push button of demonetisation," he said.
Asked about reported comments by the RSS on demonetisation, the Congress leaders said the RBI figures and facts had a strange way of being "painful, truthful and undeniable".
Earlier this week, the RBI said as much as 99 per cent of the junked Rs 500 and Rs 1,000 notes had returned to the banking system.
The RBI said in its Annual Report for 2016-17 that Rs 15.28 lakh crore of the junked currency had come back into the banking system, leaving only Rs 16,050 crore out.