UBS is one of several Swiss banks that got caught up in investigations into personal tax evasion as cash-strapped governments chased accounts hidden in Zurich, Geneva and Ticino, where wealthy Europeans had taken advantage of Switzerland's banking secrecy rules.
Investigations into tax dodging began after the state of North Rhine-Westphalia bought a CD containing details of UBS customers in 2012, which related to assets worth 3.5 billion Swiss francs ($3.5 billion).
Prosecutors have won criminal convictions in 14 cases so far, Bochum senior prosecutor Bernd Bieniossek told the Westdeutsche Allgemeine Zeitung (WAZ) newspaper in an interview published on Thursday.
Nearly all of those convicted had to pay fines, while a few were given suspended prison sentences.
A further 340 cases were closed without criminal charges in exchange for fines totalling 16.4 million euros ($17.8 million), while other cases were dismissed or referred to prosecutors outside North Rhine-Westphalia, the prosecutor said.
Bieniossek told the paper that 400 cases were still pending in Bochum.
UBS could not immediately be reached for comment on Thursday morning.