Nigerian Security agents have raided offices of black market currency dealers accused of exchanging the naira at a rate lower than the agreed 400 naira to $1.
One trader told the BBC that several people had been arrested by officers of the Department of Security Services (DSS) this morning in the capital, Abuja.
Nigeria is in the grip of a recession that has increased the cost of living
The currency was floated on the international currency markets in June after previously having been set at a fixed exchange rate with the US dollar.
However the government last week ordered security forces to crack down on currency dealers in the wake of the central bank’s apparent inability to stop the naira’s slide.