Mireille Knoll was found dead inside the blackened remains of her apartment, which police believe was set ablaze after she was attacked, a judicial source said.
Two suspects were detained but have not yet been charged.
The investigation by the Paris prosecutor’s office is trying to establish whether it was a killing “motivated by the real or supposed adherence to a religion”, the source said.
France‘s chief rabbi described Ms Knoll’s death as a “horror”. Jewish leaders have called for a march in her memory.
French foreign minister Jean-Yves Le Drian, who is visiting Israel, said the theory that Ms Knoll’s death was antisemitic was plausible.
“It reminds us of the fundamental and permanent side of this battle” against antisemitism, he said, speaking alongside prime minister Benjamin Netanyahu after visiting the Yad Vashem Holocaust museum.
As a child in Paris, Ms Knoll managed to evade the roundup of Jews during the Second World War, Paris lawmaker Meyer Habib said.
Thousands of Jews were brought to the Velodrome d’Hiver cycling track in 1942 and sent on to Nazi death camps.
France is home to Western Europe’s biggest Jewish population and many in the 400,000-strong community have complained for years of a rise in antisemitic hate crimes.
In 2015, vandals desecrated 250 tombstones in a Jewish cemetery in eastern France days after four Jews were killed in an attack on a kosher grocery in Paris.
Ms Knoll’s killing took place a year to the day after the murder of Sarah Halimi-Attal, a 65-year-old whose death prosecutors believe was antisemitic.
“The horror of the crime and the violence of the executioners are identical and reflect the negation of the human face,” chief rabbi Haim Korsia said in a tweet.
Additional reporting by Reuters
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