In the previous reporting week, the forex reserves had increased by USD 1.627 billion to USD 343.005 billion, which was a lifetime high.
Foreign currency assets (FCAs), a major part of the overall reserves, dropped by USD 2.510 billion to USD 316.131 billion during the week, the RBI data showed.
Foreign currency assets, expressed in dollar terms, include the effect of appreciation and depreciation of non-US currencies such as the euro, pound and the yen, held in the reserves.
The special drawing rights with the International Monetary Fund fell by USD 61.9 million to USD 3.959 billion, while the country's reserve position with the Fund also declined by USD 20 million to USD 1.283 billion, the apex bank said.