Swiss judicial officials say they have frozen SFr800 million ($445 million) suspected to stem from bribes that a French company allegedly paid to sell warships to Taiwan.
Geneva's chief prosecutor, Bernard Bertossa, said the bulk of the funds were in accounts in Switzerland, but that accounts had also been blocked in Luxembourg and Liechtenstein.
French investigators are probing allegations that money was channelled from the former state-owned energy group, Elf Aquitaine, now part of TotalFinaElf, to help another French firm - Thomson-CSF, now called Thales - to land a controversial contract to supply Taiwan with six Lafayette frigates in 1991.
The former French foreign minister, Roland Dumas, was convicted of corruption last month for taking illegal gifts from Elf.
Bertossa's comments come after the French-Swiss newspaper "Le Temps" reported on Saturday that SFr400 million had been frozen in connection with the inquiry led by Geneva investigating magistrate, Paul Perraudin.
But Bertossa said on Tuesday that the actual amount was nearly double that. But he declined to reveal the names of banks in several Swiss cantons where the accounts are blocked.
Last May, Credit Suisse Group reported that it had frozen more than SFr250 million in deposits it thought were linked to the warship case.
Le Temps reported that accounts had been frozen at Julius Baer, Banca della Svizzera Italiana (BSI), owned by the Italian insurer Assicurazioni Generali, and the Swiss-based private Bank Sarasin.
Bank Sarasin said on Monday it had blocked some client accounts on suspicion that the funds might be related to what it called an international corruption scam.
A bank spokesman, Urs Fazis, declined to identify the account holders or reveal the sums involved, but stressed that the bank's internal controls had noticed the suspect accounts last week.
On Friday, a Liechtenstein court froze nearly $33 million in accounts linked to the same case and on Saturday, Baer said it had also turned up suspect money that it said could total as much as SFr400 million.
swissinfo with agencies