The US dollar's exchange rate on the Khartoum black market in Khartoum has risen to a SDP 60.6 selling rate and SDP 55.6 buying rate, up from SDP 55.6 and SDP 50.6 last week.
Some have put the rise down to increased demand for US dollars by importers despite the dollar shortage in the market. Observers say the value of the US dollar will continue to rise if the implementation of the September 2012 cooperation agreement between Sudan and South Sudan isn't implemented.
The value of the Saudi rial has also increased markedly to SDP 170 selling rate and SDP 156 buying rate.
The price hike coincides with intensive campaigns conducted in recent months by security authorities against black market currency trading.
The Central Bank of Sudan has revealed it may alter the official value of the US dollar within the coming few days. Governor Badr el-Dine Mahmoud said the country's foreign currency reserves had risen recently and can now cover Sudan's needs for several months.
The official exchange rate for the US dollar in Sudan is SDP 5.395.