The Libertad was detained in the Ghanaian port of Tema on October 2 under a court order obtained by NML Capital Ltd, an affiliate of investment firm Elliott Management.

The frigate was seized in Ghana to help bondholders try to recoup debts from the South American country's 2002 default.

The firm says Argentina owes it over US$300 million on defaulted sovereign bonds and it will only release the ship if the country pays it at least US$20 million.

President Cristina Fernandez, according to Argentina's foreign ministry, said the crew's human rights were being violated because the judge had prohibited fuel deliveries to the ship - leaving it without power needed for plumbing, electricity, keeping food fresh and responding to emergencies such as a fire.

Argentina has condemned the seizure, said it could not be targeted by creditors due to the ship's military nature, and vowed to press its case at the United Nations. A Ghanaian court ruled that Argentina forfeited such immunities when it issued the bonds.

Argentina declared a massive sovereign default a decade ago at the height of an economic crisis and now faces a raft of lawsuits in US courts by so-called holdout bondholders seeking state asset freezes to recover the value of defaulted bonds.

The bondholders, which the Argentine government calls vulture funds, normally target foreign bank accounts held by state-run companies or government agencies.