Egypt's Court of Cassation, the country's top appeals court, upheld on Thursday a five-year prison sentence against a top ranking policeman for the unintended murder of 37 supporters of ousted Islamist President Mohamed Morsi in 2013.
The sentence against Lieutenant Colonel Omar Farouq cannot be appealed.
Three other co-defendants in the case received one-year suspended sentences in 2015.
The case dates back to August 2013, when police shot teargas into the back of the police van transporting suspects to Abu Zaabal prison in Qalyoubiya, north of Cairo.
The incident took place days after security forces broke up protest camps by Morsi supporters in Cairo and Giza on 14 August.
Prosecutors said at the time that 45 prisoners were being held in the transport van, which was not suited to carry more than 24 people.
The interior ministry said at the time that the prisoners were trying to escape from the vehicle, and that they had taken a police officer hostage.
However, prosecutors later said there had been no escape attempt.