Arlette Ricci was also fined and ordered to pay back taxes in the first ruling involving a famous name in the so-called Swissleaks scandal, in which a former HSBC employee gave authorities thousands of names of suspected tax evaders. Other trials are expected to follow.
A Paris court convicted Ricci, granddaughter of designer Nina Ricci, of tax evasion and money laundering and sentenced her to three years in prison, with two of them suspended. The court ordered a 1 million euro ($1.1 million) fine and the confiscation of two properties worth 4 million euros.
Ricci's lawyer Jean-Marc Fedida denounced what he said was the severity of the sentence, saying the "glamor" side of his client gave the court a chance to make her an example to deter other would-be tax fraudsters.
"The court took an extremely severe decision within an extremely difficult context under a lot of pressure," Fedida said, adding that he is deciding whether to appeal. He said he may ask the judge to let his client serve the prison term under less strict conditions, such as partial liberty or wearing an electronic bracelet.
Court documents quoting wiretaps appeared to show that Ricci was well aware of her illegal actions.
In one phone conversation, she said, laughing, "I believe I did the right thing and I never heard from Bercy, so all is well," referring to a name for the French Finance Ministry.
"Yes, inevitably, necessarily because all that is illegal anyway," she added.
It was not clear to whom she was speaking.
In both 2007 and 2008, when she became an heiress, Ricci declared an income of 2,047 euros from "pension and retirement." She also declared assets worth 8.3 million euros in 2007 and 6.3 million euros in 2008, for which she was liable to pay French wealth taxes.
In a separate part of the case, the court ordered Ricci, a lawyer and two companies to pay millions in back taxes for the period of 2007-2009. The court did not set the amount of the back tax payment, saying that would be worked out at a later date.
Arlette Ricci's daughter, Margot Vignat, 51, was also convicted and given an 8-month suspended sentence. In addition to the other fines, Vignat and Ricci were ordered to pay 100,000 euros in damages to the French government.
Ricci was one of thousands of suspected tax evaders on the original list of accounts leaked to French tax authorities in 2008 by former employee Herve Falciani. France shared the list with other governments and launched investigations.
Last week, French authorities placed London-based HSBC under formal criminal investigation over alleged tax fraud by its Swiss private bank. The bank said the claim was "without legal basis."