Charges against unnamed individual follow publication of journalistic investigation and PricewaterhouseCoopers complaint.

An investigating judge in Luxembourg has charged an unnamed individual with theft and other criminal offences after a complaint was brought by PricewaterhouseCoopers in the wake of a leak of hundreds of confidential tax deals exposing avoidance by multinational corporations.

Last month journalistic investigations into PwC tax deals were published by the Guardian and more than 20 media organisations around the world linked to the International Consortium of Investigative Journalists, sparking an international scandal that continues to threaten the position of the new European commission president, Jean-Claude Juncker.

Juncker stepped down as prime minister of Luxembourg last year after almost two decades at the helm, dominating politics, setting tax policy and aggressively courting investment from multinationals.

In a short statement, the Luxembourg authorities said charges had been brought for theft, professional secrecy violations, trade secrecy violations and illegal obtaining of data.

The action followed a PwC complaint submitted in June 2012.

The Luxembourger Wort newspaper reported that it understood the person charged to be a French national who had previously worked at PwC.

Recent press reports on the leaked papers reveal how far the firm in Luxembourg was pushing tax rules, aggressively exploiting gaps between tax codes in different countries. The confidential papers laid bare how accommodating the Luxembourg tax office had been, turning the tiny nation of 550,000 people into a honeypot for global firms looking to massage down their tax bills.

The revelations last month sparked an emergency debate in the European parliament and an unsuccessful censure vote against Juncker. Finance ministers in France, Germany and Italy wrote to the commission demanding a faster crackdown on loopholes exploited by big business.

The UK parliament’s public accounts committee this week summoned PwC to give evidence alongside its FTSE 100 tax client Shire, the drugs firm which moved tax domicile to Ireland six years ago for tax reasons. The committee’s chair, Margaret Hodge, accused PwC’s UK head of tax, Kevin Nicholson, of lying about the saga. Hodge told him: “I think what you are doing is selling tax avoidance on an industrial scale.”

Nicholson denied the tax services sold by PwC were mass-marketed schemes and said about 80 of the Luxembourg rulings related to UK firms, were all distinct and had been disclosed to HMRC.

In the aftermath of the tax leaks scandal, Luxembourg’s finance minister, Pierre Gramegna, struck a conciliatory note on the international stage, telling a meeting of European finance ministers: “We are a country that wants to combat abuse … If we want to find solutions to this issue we have to tackle it together.”

Speaking to a domestic audience, however, he has described the affair as “the worst attack Luxembourg has experienced in its history”.