The court said that Aliev and Alnur Musaev led an organized criminal group for more than a decade, even while they were high-ranking officials in the Kazakh government.
They also allegedly stole from the state, sold state secrets, and organized a group of fighters who could "physically remove inconvenient political figures" in Kazakhstan.
Aliev, who was married until late last year to Nazarbaev's eldest daughter Darigha, and Musaev, the former head of the National Security Committee, were tried in absentia and each sentenced to 20 years in jail. Both men have been outside the country for more than a year.
At a separate trial that ended in January, Aliev and Musaev were found guilty of extortion, robbery, kidnapping three Kazakh bank officials (two of whom are still missing), organizing a criminal group, misappropriation of state property, and fraud. Aliev was sentenced to 20 years in prison and Musaev to 15 years.
Aliev has also served as a senior tax official, a two-time ambassador to Austria, and a deputy foreign minister. He also headed Kazakhstan's Olympic Committee and was the country's special representative to the OSCE.
Believed to be living in Vienna, Aliev has maintained his innocence and says he is a victim of political persecution. He is expected to release a book soon that he says will shed light on corruption in the Kazakh government. Musaev's whereabouts are unknown.
Aliev was married to Darigha Nazarbaeva for more than 20 years. It is not known if she testified against her former husband.RFE/RL Kazakh Service Director Merhat Sharipzhan contributed to this report