Senior executives of IKEA France are being held by police over allegations that they illegally spied on employees and customers.
IKEA France has sacked four employees and instituted a code of conduct in response to the investigation, which began in April 2012.
French officials close to the case said IKEA France CEO Stefan Vanoverbeke and its finance chief, Dariusz Rycher, were apprehended yesterday and were questioned for a second day today.
Under French law the men must be freed within 24 hour or formally charged.
Two unions have filed complaints against IKEA, accusing them of spying on hundreds of employees and customers over at least five years.
IKEA France is a subsidiary of Swedish furniture giant IKEA.