A French court has ordered Ikea to pay €1m in fines and convicted the former chief executive of its French business for organising a broad spying operation that ensnared employees.

The criminal court in Versailles ruled on Tuesday that Ikea used private detectives and “fraudulent methods” to dig up information on employees and job applicants between 2009 and 2012, according to Agence France-Presse.

Prosecutors were pushing for a €2m fine against the world’s biggest furniture retailer, which is owned by the Ingka Group, as well as a prison sentence for the French subsidiary’s former chief executive, Jean-Louis Baillot.

Baillot, who was at the helm of Ikea France from 1996 to 2009, was found guilty and received a two-year suspended prison sentence along with a €50,000 fine.

“Mr Baillot is very shocked by this judgment,” said the former chief executive’s lawyer, François Saint-Pierre. “He denies having given instructions to spy on Ikea employees, and he plans to appeal.”

The case has sparked a lot of public interest in France, even though it centres on events from a decade ago, because it feeds into current tensions between employers and unions and concern about the misuse of personal data and privacy rights.

The scandal came to light in 2012, when police raided Ikea’s French headquarters at Yvelines, near Versailles. The officials seized documents and checked computers after a preliminary judicial inquiry had been opened into allegations of illegal surveillance made by members of two trade union groups.

The court found on Tuesday that management used a private security firm, Eirpace, to illegally obtain police records and collect personal data.

As well as the two-year suspended prison sentence Baillot received, Jean-Francois Paris, who was head of risk and conducted mass checks of employees for Ikea France from 2002 to 2012, was sentenced to an 18-month suspended prison term and given a €10,000 fine, according to AFP.

Critics said at the time that Ikea’s secretive culture had been strained by rapid expansion into new countries. The company also faced a bribery scandal in Russia about the same time as its problems in France.

But it has continued to open up over the past decade, giving greater insight into its business and balance sheet, revealing its profits for the first time in 2010 and explaining more about its complicated organisational structure.

After the ruling on Tuesday morning, Ikea France said it had “apologised for this situation which seriously undermined the company’s values and ethical standards” and that it “strongly condemned the practices of its former employees”.

This article has been corrected to state that Jean-Louis Baillot was CEO of Ikea France from 1996 to 2009