France's top administrative court has backed privacy campaigners by imposing a ban on police use of drones for covering public protests in Paris.
The Council of State said Paris police prefect Didier Lallement should halt "without delay" drone surveillance of gatherings on public roads.
The move comes as parliament discusses a contentious security bill that includes police use of drones.
Its main aim is to regulate how people share film or photos of police.
Privacy rights group La Quadrature du Net (LQDN) has argued that the bill's main measures violate freedom of expression and that drones equipped with cameras cannot keep the peace but track individuals instead.
The Council of State ruled there was "serious doubt over the legality" of drones without a prior text authorising and setting out their use. LQDN said the only way the government could legalise drone surveillance now was in providing "impossible proof" that it was absolutely necessary to maintain law and order.
The decision is the second setback in months for Parisian authorities' drone plans. In May, the same court ruled that drones could not be used in the capital to track people in breach of France's strict lockdown rules.
Under article 22 of the security bill currently going through parliament, security forces would be allowed to send images filmed by drone or helicopter to command teams and retain those images for 30 days or more as part of a possible police inquiry.
Protests broke out after the bill passed its first reading in the National Assembly, with most of the anger directed at article 24, which makes it a criminal offence to publish images of on-duty police officers with the intent to harm their "physical or psychological integrity".
Images also emerged of three police kicking and punching Michel Zecler, a black music producer, in Paris. Campaigners argued the new bill would prevent people from exposing police brutality.
President Emmanuel Macron said the images were unacceptable and his ruling party promised to rewrite article 24.
In a separate development, judges on Tuesday ordered the release of the police officers taken into custody over the attack on Mr Zecler, subject to conditions.