Taiwan has asked Switzerland to return $520 million (SFr646.7 million) frozen in Swiss banks following a probe into a corruption affair.
The Federal Justice Office in Bern confirmed on Friday that a request was received three days ago and the case was now in the hands of an examining magistrate.
The affair, dating back to 1991, involves the controversial $2.5 billion (SFr3.25 billion) sale of six frigates to Taiwan by the French former state-owned firm, Elf Aquitaine.
It is alleged that Elf Aquitaine, via another French firm, Thomson-CSF, paid bribes to persuade French and Taiwanese authorities to approve the sale of the warships.
Investigations began after Taiwanese authorities concluded from the inflated price that the deal constituted a serious case of international corruption.
Funds related to the deal remain blocked in 46 accounts in different banks in Switzerland as part of a Swiss investigation into alleged money laundering linked to the Elf case. Authorities in Liechtenstein have frozen a further $27 million.
"I can confirm that we have received a request for the restitution of the assets that have been frozen in Switzerland. The damages mentioned in the request are $520 million," Justice Office spokesman Folco Galli told swissinfo.
"After the formal preliminary examination [of the application] we will submit it to the competent federal examining magistrate and he will decide whether the assets can be restituted."
According to media reports, Taiwan considers the $520 million sum to be equal to the amount in damages it suffered over the deal.
Last year the Swiss government granted judicial assistance to Taiwan in connection with the case.
The Federal Court ruled in October 2005 that bank documents related to the case could be handed over to Taiwan after receiving assurances from Taipei that it would not use the death penalty against anyone convicted in the case.
This had been the concern of the main suspect in the affair, local Thomson agent Andrew Wang, who had appealed against the initial ruling to grant assistance. Swiss authorities rejected his request.
"Judicial assistance has already been granted to hand over evidence like bank documents and now Taiwan has asked for restitution of the funds," said Galli.
"An appeal is only possible once an examining magistrate has ordered the restitution."
The six warships were sold in 1991 to the Taiwanese navy by the French firm Thomson-CSF.
The deal cost Taiwan $2.5 billion.
Former arms dealer Andrew Wang, who was a local Thomson agent in Taiwan, is suspected of having paid bribes to Taiwanese officials to secure their agreement on the deal.
$100 million was allegedly paid to the Chinese communist party to persuade it to accept the sale of the ships to the "rebel" province.