The Swiss National Bank starts to look for a new board member today after its president resigned amid reports of controversial currency trading by his wife.

Switzerland’s central bank was due today to begin searching for a new board member after Philipp Hildebrand resigned yesterday as chairman following the revelation of his wife’s currency trading activities just weeks before a key forex policy announcement.

The saga at the Swiss National Bank, as has been previously reported, included the arrest and dismissal of an employee of Sarasin, the Swiss private bank. A lone employee at the firm’s IT department had passed on data to a third party regarding the Hildebrand case. (To view more on the case, click here).

Hildebrand's wife Kashya, a former hedge fund trader who now runs a Zurich art gallery, bought SFr400,000 of dollars on 15 August, three weeks before her husband oversaw moves to prevent the Swiss franc’s rise, as this was harming Swiss exporters. She later sold the dollars at a higher rate.

“For the time being, the vice chairman, Thomas Jordan, will hold the position of chairman of the SNB governing board. The decision-making capacity of the governing board and its capacity to act remain fully guaranteed. The free position in the governing board is to be filled as soon as possible,” the bank said in a statement yesterday.

In his resignation statement, Hildebrand said: “In view of the continuing public debate centred on these financial transactions, and following detailed examination of all the documents and thorough reflection since the news conference, I have come to the conclusion that it is not possible to provide conclusive and final evidence that my wife did indeed initiate the foreign exchange transaction on the 15 August without my knowledge.”

“The fact is: my word is my bond. I had no knowledge of my wife’s transaction on that day. Unfortunately, mistakes were made in connection with these transactions. I detailed these on Thursday, and I apologise for them. I deeply regret these mistakes as well as the entire situation. At least these mistakes have made it possible for us to identify weaknesses in the SNB’s internal regulations, as well as its requirements in terms of transparency and code of conduct. The focus now should be on resolutely eliminating these weaknesses. This will allow the SNB to retain its credibility, which is its greatest asset,” he said.

The developments come at a sensitive time for Switzerland as a financial centre. Its banking industry – long known for its secretive bank laws – is under relentless international assault and a number of its largest firms, such as UBS, have been embroiled in legal wrangles in the US surrounding alleged help for tax evaders. The latest example of such a bank to be threatened with action is Wegelin, the venerable private bank (to view more on this issue, click here). The SNB, along with regulatory authorities, has overseen moves to increase capital requirements for banks in the wake of the big losses sustained in the 2008 credit crunch.

Jordan, the vice chairman now taking Hildebrand’s post, has headed the financial markets unit and for the past two years has overseen the regulatory department - a key area at a time when the Swiss banking industry has been recovering from heavy losses at firms such as UBS.

Yesterday, Jordan reportedly said he is prepared to take the top job on a permanent basis if the government asks him to do so.