The Swiss banking giant UBS went on trial in Paris on Monday over accusations it illegally helped wealthy French clients move their money out of the country and beyond the reach of tax authorities, charges which could land it with billions of euros in fines.
After a six-year investigation, judges last year charged the bank and its French subsidiary with laundering proceeds from tax fraud carried out from 2004 to 2012, allegations the bank has denied.
"UBS will finally have the chance to respond to what are usually unfounded claims," the bank has said, vowing to "strongly defend itself."
Six bank managers and former managers are also on trial, including Raoul Weil, the former third-in-command at UBS, and Patrick de Fayet, formerly the second-ranking executive for its French operations.
The inquiry was opened after a former employee alerted authorities over the bank's alleged system of setting up dual bookkeeping to hide the movement of capital into Switzerland. France's national financial crimes unit estimates at least 9.76 billion euros (USD 11.2 billion) was not reported to the French tax authorities.
The bank's staff allegedly approached French clients, from wealthy businessmen to sports stars, at receptions, golf and tennis tournaments or concerts to convince them to hide their money in Switzerland.
If convicted UBS could face fines of up to half the amount of money laundered or nearly five billion euros. Outside the courtroom a former American UBS banker turned whistleblower, Bradley Birkenfeld, offered copies of his book "Lucifer's Banker: The Untold Story of How I Destroyed Swiss Bank Secrecy".
Birkenfeld brought to light a conspiracy by UBS to help some 20,000 clients hide billions of dollars from US authorities from 2002 and 2007, which saw the bank pay USD 780 million to settle to the case. All smiles, he urged his "instructive" book on a UBS lawyer, who said he hadn't found the time to read it.
"Of course, you've been too busy," Birkenfeld responded.
The whistleblower in the French case, Nicolas Forissier, was sacked by UBS in 2009 for alleged "gross misconduct".
"My honour will finally be cleared," Forissier, a former internal auditing chief, said last year when judges ordered the trial after prosecutors and bank executives failed to reach a plea deal.
According to documents provided by German authorities to French investigators, deposits from some 38,000 French clients with UBS amounted to a total of around 13 billion Swiss francs (11 billion euros, USD 13 billion), a source close to the case told AFP.
Not all these clients are suspected of tax fraud, the source said. UBS has faced a series of fraud cases in other countries in recent years. Belgium has also indicted the bank for organized tax fraud, while it has also paid fines to US, British and Swiss regulators over alleged interest rate rigging.
France has cracked down hard on tax evasion in the wake of the 2008 financial crisis, not least after a former budget minister was found to have hidden money in overseas accounts. A court upheld Jerome Cahuzac's fraud conviction this year, handing him a 300,000 euro fine and banning him from public office for five years. The UBS trial is expected to run until mid-November, barring any procedural delays