Switzerland has ruled out an early handover of assets frozen in connection with a corruption case involving the sale of French frigates to the Taiwanese navy.

Federal investigating magistrate Paul Perraudin has decided the assets worth over $520 million (SFr518 million) will remain in Switzerland until Taiwan submits a court confiscation order, the justice ministry announced on Thursday.

But the judge pointed out that there were "significant indications" the funds were criminal proceeds.

Taiwan requested the handover in August 2006 as part of international legal assistance proceedings over a $2.5 billion (SFr3.25 billion) sale of six Lafayette frigates by France's Elf Aquitaine company in 1991.

It is alleged that Elf Aquitaine, via another French firm, Thomson-CSF, paid bribes to persuade the French and Taiwanese authorities to approve the sale of the warships.

Criminal proceedings are pending in Taipei against individuals accused of corruption, money laundering and other offences. Both Switzerland and Liechtenstein have blocked funds in accounts allegedly linked to the case.

In compliance with the JTI standards

More: SWI swissinfo.ch certified by the Journalism Trust Initiative