Swiss central bank chief Philipp Hildebrand has rejected criticism of foreign currency transactions by his family last year, suggesting "political motives" were at work.
Speaking publicly for the first time about the scandal, Mr Hildebrand yesterday refused to step down and said he had complied with all the regulations of the central bank.
However, he conceded he had made mistakes and that banking transparency would need to be tightened.
"I acted correctly on every count," he said following days of media speculation over allegations of insider trading on a dollar trade his wife made in August - three weeks before the Swiss National Bank put a cap on the Swiss franc at €1.20.
"So long as I have the confidence of the government and the bank council, stepping down is not an issue for me," said Mr Hildebrand.
"Looking back I made mistakes," he added, saying he could have reversed his wife's decision.
"The most important lesson I can take from the events is - another improvement of transparency in every aspect that concerns financial transactions of members of the board of the Swiss National Bank is essential."
Mr Hildebrand has been credited with increasing Swiss banking transparency after the 2008 global financial crisis.
It emerged last month, however, that his wife Kashya Hildebrand profited after buying $504,000 in August, just weeks before intervention by the SNB to halt the rise of the franc - a move that saw the dollar rise significantly against the Swiss currency.
The purchase, which investigators said appeared to have been carried out without her husband's knowledge, was deemed "sensitive" by auditors who nevertheless cleared the couple of any wrongdoing.
Pressed on not knowing about his wife's trade, Mr Hildebrand told a press conference that his wife had ''very strong opinions and is very interested in global financial markets."
Ms Hildebrand, a former hedge fund worker who now runs an art gallery, defended herself earlier this week, saying she bought the dollars due to the fact that the currency had "hit a very low level and become ridiculously cheap."
The Swiss government, whose own Federal Audit Office carried out a dual investigation exonerating the couple, is standing by the bank chief.
However, Switzerland's biggest political party today piled fresh pressure on Mr Hildebrand to quit over the currency trade scandal.
The Swiss People's Party (SVP) has also called for a special parliamentary session to examine the case.
Other political parties appeared satisfied with Mr Hildebrand's performance and his promise to improve transparency at the central bank.
Mr Hildebrand joined the SNB board in 2003 and was appointed chairman seven years later.
He is also vice chairman of the Financial Stability Board - an international body tasked with promoting financial sector reform in light of the 2008 crisis - and a member of the board of directors of the Bank for International Settlements (BIS) in Basel.
Bank Sarasin in Basel this week dismissed an employee who allegedly transmitted transaction details to a lawyer close to the far-right Swiss People's Party whose chief Christoph Blocher is a Hildebrand critic.
Zurich prosecutors have launched a criminal case against a 39-year-old former bank worker.
