Halle and Gabriel are embroiled in a court battle over whether the mother should be allowed to move to the European country - where her fiance Olivier Martinez is from - with their young girl.
The actress believes their offspring will be better protected from aggressive paparazzi in France due to the country's strict laws about professional celebrity photographers.
But Gabriel's attorney argued Halle and Nahla would be making the situation worse as France is the same country where Princess Diana was killed in a wild paparazzi car chase back in 1997, according to website TMZ.com.
Halle's lawyer called several French lawyers - who testified that French judges will punish any photo press members who pursue the family, Contactmusic reported.
Under French laws, paparazzi cannot photograph famous people who don't want their pictures taken, even if they're out in public. Photographers who violate the law can be sued and if they harass the well-known person they can be criminally prosecuted.