The country's forex reserves dropped by a further $8.48 billion to $644.39 billion for the week ended December 20, the RBI said on Friday.
In the previous reporting week, the reserves had dropped by $1.988 billion to a six-month low of $652.87 billion.
The reserves have been declining for the last few weeks, and the drop has been attributed to revaluation along with forex market interventions by RBI to help reduce volatilities in the rupee.
The forex reserves had increased to an all-time high of $704.88 billion in end-September.
For the week ended December 20, foreign currency assets, a major component of the reserves, decreased by $6.01 billion to $556.56 billion, the data released on Friday showed.
Expressed in dollar terms, the foreign currency assets include the effect of appreciation or depreciation of non-US units like the euro, pound and yen held in the foreign exchange reserves.
Gold reserves decreased by $2.33 billion to $65.73 billion during the week, the RBI said.
The Special Drawing Rights (SDRs) were down by $112 million to $17.88 billion, the apex bank said.
India's reserve position with the IMF was also down by $23 million to $4.22 billion in the reporting week, the central bank data showed.