Prosecutors probe whether anti-Semitism was a motive for killing of Mireille Knoll who was stabbed 11 times and left in her burning Paris flat.
The head of the far-right party's branch in Nice, Benoît Loeuillet, was recorded in an undercover interview for a TV documentary as saying that the mass extermination of six million European Jews during WWII did not happen.
Jean-Marie Le Pen, 87, was convicted of contesting crimes against humanity with remark that WWII extermination gas chambers were "a detail" of history.
France and the US announced a 60M-dollar reparation agreement to be paid to non-French survivors and relatives, ending any further legal claims.
American Holocaust survivors who were deported to death camps by French state rail firm SNCF will get compensation from €49m fund.
White House warns US states not to take action that could harm talks with French rail firm SNCF which deported Jews to WW2 death camps.
The move comes three years after railway formally admitted it transported thousands of Jews to their deaths during the Second World War.
President François Hollande led a ceremony at a former WWII internment camp at Drancy, north of Paris, used in the deportation 65, 000 Jews.
President Hollande's commemoration of 1942 Vél d'Hiv roundup of Jews was important for addressing European anti-Semitism, argues Denis MacShane.
President Hollande has recognised France’s role in the Holocaust at a ceremony to mark the 70th anniversary of a round-up of 13,000 Jews in Paris.