Luxembourg's highest court overturned a previous verdict of a six-month suspended jail sentence and a €1,500 fine against Antoine Deltour, a French whistleblower involved in the LuxLeaks scandal on Thursday (11 January).
But his former colleague and fellow leaker Raphael Halet's sentence of a €1,000 fine was upheld by the court.
The court ruled that Deltour has to be recognised as a whistleblower, while Halet does not meet the necessary criteria.
The two men, former employees of consultancy firm PricewaterhouseCoopers (PwC), were accused of stealing documents from their employer in 2014 that showed how the company helped several multinationals to evade taxes in Luxembourg from 2002 to 2010.
Edouard Perrin, a French journalist, was the first to reveal the documents, which became the so-called 'LuxLeaks' in 2014, but he was originally acquitted twice.
Luxembourg's justice said that the case will subject to a further appeal by an appeal court to decide if Deltour has to be sanctioned for appropriation of some internal PwC's training documents, which were not disclosed.
In the wake of LuxLeaks' revelations, the European Commission and member states decided to take new measures against tax avoidance and tax dumping.
A tempered victory
As he left the court, Deltour called the verdict a "victory."
However, Deltour' satisfaction was "lessened for the different treatment of Raphael Halet's case," the French whistleblower wrote in a tweet.
Deltour and Halet "should never have gone to trial" since in the absence of greater tax transparency, "whistle-blowing is often the only way tax dodgers are exposed," the global NGO Oxfam said.
The day before the verdict, spokesperson for economic and financial affairs for the Greens/EFA group at the European Parliament Sven Giegold MEP said that "whoever averts billions of euros in damage to the common good must not be punished."
The Green/EFA group said on Twitter members were "happy" for Deltour's trial outcome, but vowed to continue their call for EU whistleblower protection to "ensure future whistleblowers don't face the same ordeal."
Transparency International called for such legislation to "ensure that those who reveal wrong-doing are not punished for speaking out."
However, despite the commission saying that a proposal should be tabled in the course of the spring of 2018, nothing has come yet.
The protection of whistleblowers currently depends on member states legislation and rules differ from one state to another.
The parliament has called several times on the commission to take action.
In December 2017, the parliament's Panama Papers investigative committee called for expanded whistleblower protection, following an 18-month investigation that leak.