It would be the first trial of policemen accused of killings in a massive crackdown on Islamists which followed the army's July 3 ouster of elected president Mohamed Morsi.
The officers are charged with manslaughter, MENA reported. They include the deputy head of a Cairo police station from where the prisoners were being transferred.
The prisoners, arrested during clashes with security forces, died from suffocation when police fired tear gas canisters into the truck transporting them to a prison on Cairo's outskirts, the interior ministry said at the time.
The incident sparked international condemnation, with UN Secretary General Ban Ki-moon calling for an investigation into the prisoners' deaths.
It took place four days after police dispersed two Islamist protest camps in Cairo, killing hundreds in clashes.