The justice authorities in canton Geneva have launched a money laundering investigation against Jean-Christophe Mitterrand, the son of the late French president jailed in France on suspicion of illegal arms trading.
The cantonal prosecutor, Bernard Bertossa, said eight bank accounts in Geneva and Zurich had been frozen in connection with the case.
They were blocked following a request for legal assistance by French prosecutors.
Bertossa said the French request for help had allowed the Swiss authorities to locate accounts "whose funding can be considered suspect".
Mitterrand is suspected of receiving at least $1.8 million for his part in helping organise an illegal arms deal between Russia and Angola in 1993 and 1994. It is thought the payments were made in four instalments in 1997 and 1998.
He has admitted to receiving funds via a Swiss bank account but says the money was payment for helping with a legal, inter-government oil deal.
Mitterrand was his father's adviser on African affairs from 1986 to 1992.
The 54-year-old has been behind bars in France since December 21, 2000 and is expected to post bail on Thursday.
swissinfo with agencies