Nigerian President Olusegun Obasanjo's official visit to Bern on Thursday is expected to focus on the ongoing issue of funds hidden in Swiss banks by former dictator Sani Abacha.
While Switzerland has ensured most of the money has been returned, some funds are being held because of concerns over their use back in Africa.
Obasanjo is to meet Swiss President Moritz Leuenberger on Thursday. The two men will discuss the return of the Abacha funds as well migration issues and economic ties, according to Leuenberger's office.
The presidents already met in January on the sidelines of the World Economic Forum's annual summit in Davos.
Between 1993 and 1998, Sani Abacha is believed to have plundered more than $2.2 billion (SFr2.86 billion) from state coffers in Nigeria. About $700 million was frozen in Switzerland in 1999, shortly after the dictator's death from an apparent heart attack.
Despite attempts from Abacha's family and associates to have the funds handed over to them, the Swiss courts ruled that the money should be returned to the Nigerian government.
More than $200 million was returned to Nigeria in a first payment in December 2003. The Federal Court last year ordered that a further $458 million be released, after throwing out appeals from the Abacha family.
Subsequent payments have been made through the World Bank and the Bank for International Settlements in Basel. But $50 million is still blocked over concerns that the money would not be used for development projects in key sectors such as health, education and basic infrastructure.
Switzerland and Nigeria last September signed an agreement stipulating that the use of returned funds would be monitored by the World Bank, after Obasanjo accused Switzerland of stalling payments.
Nigeria has also been pushing, with some success, for the return of Abacha's looted funds from other countries, including Britain, Luxembourg, Liechtenstein and Austria.
Discussions between Leuenberger and Obasanjo over migration are likely to focus on asylum. The number of Nigerian asylum seekers peaked in 2002 in Switzerland, totalling nearly 1,100.
At the time, Nigerians constituted the fourth largest group of asylum seekers behind citizens of Serbia-Montenegro, Turkey and the former Yugoslav Republic of Macedonia.
This figure has dropped significantly since then, falling to levels similar to those found in the mid-1990s. The Federal Migration Office has also extended a programme to encourage those whose requests have been turned down to return home.
The Swiss launched the programme in 2003 as part of a readmission accord with Nigeria. Asylum seekers who arrived before January 1 this year will receive financial aid if they accept to go back home.
An individual can get up to SFr2,000 from the Swiss, another SFr5,000 for projects in Nigeria as well as support from cantonal authorities before heading back.
Economic ties will also feature strongly at the talks in Bern. Nigeria is Switzerland's third-biggest trading partner in Africa behind South Africa and Libya, and its second-biggest oil supplier.
Obasanjo will also meet with Swiss business representatives after completing his discussions with Leuenberger.
swissinfo with agencies
According to the Swiss Bankers Association, Switzerland probably has the world's most comprehensive and effective mechanism for dealing with money from criminal sources.
The 1998 Money Laundering Act obliges all financial intermediaries to identify all clients and beneficiaries of assets.
They must also report any justified suspicion of money laundering to the authorities and freeze suspicious assets.
But the association says that due to the large amount of foreign asset management in Switzerland, the chances of a dictator stashing illegal funds in Switzerland is relatively high.
Nigeria is the most populated country in Africa, with more than 120 million inhabitants and 250 ethnic groups.
The country is a federal republic, made up of 36 states plus the Federal Capital Territory of Abuja.
Nigeria re-achieved democracy in 1999 after a 16-year interruption by a series of corrupt and brutal military dictators.
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