ZURICH  - Swiss central bank head Philipp Hildebrand came under pressure on Wednesday following revelations of sensitively timed currency trades by his wife and the sacking of a whistleblower who passed details to the lawyer of a political adversary.

The employee of Bank Sarasin was fired for leaking data showing that Hildebrand's wife Kashya, a former trader who owns a Zurich art gallery, bought dollars three weeks before the central bank capped the Swiss franc. The case goes to the heart of Switzerland's bank secrecy.

Kashya told Swiss television she "felt good" about the deal last August that local tabloid Blick reported had yielded a 60,000 Swiss franc ($64,400) profit on a 500,000 franc trade.

"What motivated me to buy dollars was the fact that it was at a record low and was almost ridiculously cheap," she was quoted as saying on Swiss television. "As I have worked in the financial and banking industry for over 15 year and always observe the markets, I felt at ease with this transaction." The Swiss National Bank has already investigated Kashya's trade and said it did not infringe internal rules. On Wednesday it went a step further, releasing an internal document and a report by auditor PWC that it said showed inaccuracies in media accounts. But in a country that has been plagued by scandals linked to a banking industry that has helped the world's wealthy hide from the taxman, politicians called on the central bank to divulge its internal codes of conduct. As rumors started swirling about potential legal suits, politicians called on Philipp Hildebrand and the bank to clarify what had happened.

One central bank official called Kashya's trade "a lot for a weekend shopping trip to New York." Kashya, who was born in northern Pakistan but was brought up in America and is an American citizen, cut her teeth in trading while working for U.S. hedge fund Moore Capital, according to Swiss newspaper reports.