UBS France is being fined 10 million euros (US$13 million) after French authorities found the bank delayed tightening up controls to curb money laundering and cross-border fiscal fraud.

The French banking regulator, ACP, said yesterday that UBS France was warned by autumn 2007 about inadequate procedures and did nothing for 18 months. The statement did not specify whether there had been any illicit activity.

French prosecutors are separately investigating UBS France - and three executives - for complicity in illegal business dealings.

In a statement, the Swiss bank said its French subsidiary has been under new leadership since 2012 "and has continuously strengthened its rules and processes."

The bank said it was considering appealing the decision and has denied wrongdoing in the investigation.

The fine on UBS France comes amid heightened efforts by officials to crack down on tax evaders across Europe as governments struggle to cut debt and emerge from economic recession.

The head of the European Central Bank underlined this effort yesterday, saying after a hearing in the French parliament that there could be "no complacency" for tax cheats.

"I think there should be no doubt that tax evasion should be ... a fight that should be fought at all costs and won," ECB President Mario Draghi said.

The European Union is leading a charge to crack down on secret accounts that hide money from governments, and the Group of 20 leading industrial and developing nations has pledged to rein in tax avoidance by multinational companies.

Switzerland's banks, known for their secrecy, have long been suspected of being used to hide money from tax authorities. The Alpine country has been pressured in recent years, however, into negotiating some tax treaties with the US, Germany and others.

UBS was in the spotlight earlier this year as one of the banks where France's then-budget minister hid funds from tax authorities.