The rising crude oil price in the worldwide market has pushed Nigeria's external reserve to $40.4 billion, according to latest Central Bank of Nigeria figures.
Despite initial marginal decline on Monday, crude oil price maintained a steady climb, with latest reports showing it at $67.80 per barrel.
The CBN said Nigeria's external reserve reached the new mark on January 5.
Okorafor attributed the accumulation to CBN's strategy of effectively managing the demand for Forex by various sectors of the economy.
A breakdown of the figure indicated that the CBN offered $100 million to the Wholesale sector, while the Small and Medium Enterprises and invisibles windows each received $55 million.
In its statement on Monday, Nigeria's central bank also said it had injected $210 million into the interbank foreign exchange market on Monday, extending efforts to increase liquidity and alleviate dollar shortages.
"Citing the CBN policy restricting access to forex from the Nigerian forex market by importers of some 41 items as the major turning point, Okorafor said the policy had helped to stop the hemorrhaging of the country's external reserves, which hitherto witnessed heavy depletion due to huge import bills and other debt obligations", he said.
He added that the CBN's forex restriction policy had ensured that the nation's import bill reduced from $5 billion monthly to $1.5 billion in 2017.
Okorafor expressed confidence that the country's External Reserves will continue to swell throughout 2018.