The US$150 million Oak Finance loan was made in July.

When Banco Espírito Santo failed a month later, the Oak Finance loan was placed in a successor bank, Novo Banco, that kept the collapsed lender’s good assets.

In December, the loan was moved by the Bank of Portugal to the “bad bank” of the lender, which holds assets to be liquidated.

The NZ Super Fund is part of a group including Goldman Sachs, which arranged the loan, suing the Central Bank of Portugal over their loans being excluded from the bank’s bailout.

The Super Fund confirmed today that it would be taking action in the English courts, and would also be filing public law proceedings in Portugal against the Bank of Portugal, challenging the validity of the Bank’s decision purporting to retransfer the Oak Finance loan, with retroactive effect, from Novo Banco to Banco Espirito Santo.

In a statement, the group taking action said: “In August 2014, when faced with the likely failure of BES, the Bank of Portugal directed that senior obligations of BES, including the Oak Finance loan, be transferred to Novo Banco along with the assets and other senior debt of BES. The Bank of Portugal's subsequent decision in December 2014 purporting to determine, with retroactive effect as of August 3, 2014, that the Oak Finance loan had not transferred to Novo Banco was based on incomplete and inaccurate information. The Oak Finance investors do not accept that the Bank of Portugal had any legal grounds justifying the December 2014 decision. Although the Bank of Portugal has since been provided with facts that would require it to reverse its December decision, the Bank has refused to do so, instead referring these matters to be determined by a court.”