The Dangote Group, which counts cement and fertiliser manufacturing and sugar refining among its businesses, is owned by Africa's richest man Aliko Dangote. Dangote is also readying a 650,000 barrels per day oil refinery that cost $20 billion to build.
Under former Central Bank of Nigeria (CBN) governor Godwin Emefiele, the bank had multiple exchange rates and sold dollars cheaply to some businesses, including Dangote, to help them import raw materials.
A Dangote spokesperson did not immediately respond to requests for comment.
Two people at the Economic and Financial Crimes Commission (EFCC) said Thursday's search at Dangote offices in Lagos, was part of an investigation set to be expanded to other companies.
"We went to the head office of Dangote Group today to look into their books on the ongoing investigation on the abuse of the extant laws that govern the foreign exchange transaction during the tenure of Godwin Emefiele as CBN governor," one of the sources told Reuters.
"Here, we are talking about multiple exchange rates and others. It is an ongoing investigation and it was the turn of Dangote Group today," said the source, who declined to be named because he is not authorised to speak on the issue.
EFCC spokesperson Dele Oyewale declined to comment.
A second source confirmed the investigation, adding that at least one other listed Nigerian conglomerate would be targeted.
By Camillus Eboh, Reuters
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