166.—(1) For the purpose of proving a debt incurred or payable in a currency other than sterling, the amount of the debt shall be converted into sterling at the official exchange rate prevailing on the date when the investment bank entered special administration.
(2) “The official exchange rate” means the mean of the buying and selling spot rates prevailing in the London market as published at the close of business for the date in question. In the absence of any such published rate, it is such rate as the court determines.