French authorities say Renault and one of its executives or their representatives, are due to attend a defamation hearing on 4 April near Paris.

Just-auto has learned lawyers acting for senior Renault executive Bertrand Rochette have filed the defamation complaint following the suspension of three employees at the manufacturer, as the alleged espionage case continues.

"Renault and Rochette or their representatives must be present on this date," a spokeswoman for the Tribunal de Grande Instance de Nanterre near Paris, told just-auto.

"[The] citation [is] for non-public defamation, which is a fifth class contravention. It goes to a hearing on the 4 April this year at Boulogne-Billancourt - we are only observers. We have no details as we don't have the details in hand. It is something in the hands of the lawyers."

Rochette has reacted angrily to what he perceives as unfair categorisation and has gone public with his robust defence, courting the French media in a bid to establish his innocence.

Renault has not named any of the three executives, referring only to "persons unknown for acts constituting organised industrial espionage," as it initiated a judicial investigation.