The 39-year-old former computer technician at Sarasin bank is accused of taking details of a currency deal made by Hildebrand's wife and passing this information to the conservative Swiss People's Party, whose chief Christoph Blocher is a Hildebrand critic.
Citing anonymous sources, the SonntagsZeitung reported the technician had been sent to hospital after the suicide attempt.
At the start of January, the man turned himself over to police. He is the subject of a criminal probe, while Hildebrand has not faced a criminal enquiry.
The scandal centres on reports that Hildebrand's wife Kashya profited after buying $504,000 last August just weeks before an intervention by the Swiss National Bank to halt the rise of the franc.
The Hildebrands allegedly profited handsomely when the dollar's value soared against the Swiss franc, said the press reports.
The SNB said Saturday it would hire an outside firm to audit all banking transactions carried out by managers between 2009 and 2011.