The French branch of Swedish retailing giant IKEA went on trial this morning accused of running an elaborate system to spy on staff and job applicants using private detectives and police officers.

IKEA France, as a corporate entity, is being prosecuted in a court in Versailles, southwest of Paris, as well as several of its former executives who risk prison terms.

French investigative publications Le Canard Enchaine and Mediapart uncovered the surveillance scheme in 2012, and magistrates began investigating after the Force Ouvriere union lodged a legal complaint.

Prosecutors say IKEA France set up a "spying system" across its French operations, collecting information about the private lives of hundreds of existing and prospective staff, including confidential information about criminal records.

Since the revelations, the company has sacked four executives, but IKEA France, which employs 10,000 people, still faces a fine of up to €3.75m.

The 15 people being tried in the court include former store managers and top executives, such as former CEO Stefan Vanoverbeke and his predecessor, Jean-Louis Baillot.

Both men were present today, but declined to comment to waiting reporters.

Stefan Vanoverbeke

The group also includes four police officers accused of handing over confidential information.

The charges include illegal gathering of personal information, receiving illegally-gathered personal information, and violating professional confidentiality.

Some of the charges carry a maximum prison term of ten years.

"We're here to today to show that there are these types of actions inside companies that police trade unions and above all their employees," a senior member of the CGT union, Amar Lagha, told reporters.

At the heart of the system allegedly was Jean-Francois Paris, IKEA France's former director of risk management.

Prosecutors say he regularly sent lists of names to be investigated to private investigators, whose combined annual bill could run up to €600,000, according to court documents.

The court is investigating IKEA's practices between 2009 and 2012, but prosecutors say they started nearly a decade earlier.

Among the targets was a staff member in Bordeaux "who used to be a model employee, but has suddenly become a protester", according to an email sent by Mr Paris. 

"We want to know how that change happened," he said, wondering whether there might be "a risk of eco-terrorism".

In another case, Mr Paris wanted to know how an employee could afford to drive a brand-new BMW convertible.

Such messages usually went to Jean-Pierre Fources, the boss of surveillance company Eirpace. 

He would then send Mr Paris confidential information, which prosecutors say he got from the police database STIC with the help of the four officers.

Prosecutors say the information flow may even have gone both ways, with an internal IKEA France document recommending handing over its report about an employee to police "to get rid of that person via a legal procedure outside the company".

Emmanuel Daoud, a lawyer for IKEA France, acknowledged that the case had revealed "organisational weaknesses".

He said the company had since implemented an action plan, including a complete revamp of hiring procedures.

"Whatever the court rules, the company has already been punished very severely in terms of its reputation," he said.

Founded in 1943, Swedish multinational IKEA is famous for its ready-to-assemble furniture, kitchen appliances and home accessories which are sold in around 400 stores worldwide.