The cop's donations from more than 40,000 people responding to a right-wing media appeal easily outstripped the €200,000 or $210,000 gathered for the family of the dead 17-year-old, Nahel, who was of North African descent.
Nahel's grandmother said she was "heartbroken" by the support shown for the policeman.
"He took the life of my grandson. This man must pay, the same as everyone," she told the BFM channel on Sunday adding that "I have confidence in the justice system. I believe in justice."
Last Tuesday's shooting during a traffic stop in a suburb west of the French capital Paris has exposed deep political divisions in the country.
Politicians from the left and the ruling centrist party have condemned the donation efforts to the policeman, which was launched by far-right media commentator Jean Messiha.
"Jean Messiha is playing with fire," ruling party MP Eric Bothorel wrote on Twitter, calling it "indecent and scandalous."
The head of the Socialist party, Olivier Faure criticized Gofundme, saying it was facilitating a "shameful" collection.
Many right-wing figures have defended the security forces, while those on the left see the death as a result of systemic racism within the French police force.
Widespread rioting and looting since the incident appear to have deepened the polarization.
Senior hard-left MP Mathilde Panot highlighted how a donation for a former boxer who had punched police officers during "Yellow Vest" anti-government demonstrations in 2019 was quickly closed by authorities.
"Killing a young North African in France in 2023 can earn you a lot of money," she wrote.
Messiha, a former advisor to far-right leader Marine Le Pen, celebrated on Twitter when his fund overtook the one for the family of Nahel over the weekend.
When launching the appeal, he said it was for an officer who was "doing his work and is paying a heavy price."
Head of the right-wing Republicans party, Eric Ciotti, defended the donation on Monday and said he might contribute, saying that the officer's family was "facing difficulties."
The 38-year-old policeman, named by French media as Florian M., has been detained and charged with voluntary manslaughter.