Aliev -- who is married to President Nursultan Nazarbaev's influential eldest daughter, Darigha -- denies the charges. He says he's being punished for his presidential ambitions and for challenging Nazarbaev's recent move to secure himself president-for-life status.
Critics in Kazakhstan suspect that Aliev is cynically exploiting democratic slogans to further his own career.
An influential 44-year-old businessman and politician, Aliev is accused of kidnapping two senior bank officials in January -- one of whom subsequently disappeared.
In a statement published on the "Kazakhstan Today" website, Aliev rejects the charges and blames them on presidential ambitions that he says he confided in Nazarbaev earlier this year.
More recently, Aliev last week criticized amendments to the Kazakh Constitution that allow Nazarbaev an unlimited number of terms as president.
Bona Fides
But opposition credentials could prove elusive for a man who has benefited so greatly from Kazakhstan's close-knit, post-Soviet administration.
Many observers in Kazakhstan say Aliev's criticism of his father-in-law is driven by personal animosity. In a country where clan and family connections play a major role in political and business life, opposition leaders accuse both Nazarbaev and Aliev of nepotism and corruption.
Amirjan Qosanov, the deputy head of the Social Democratic Party of Kazakhstan, tells RFE/RL's Kazakh Service that Aliev's case shines a bright light on how politics work in this hydrocarbon-rich former Soviet republic.
"What we have now reflects the true situation in Kazakhstan's political structure," Qosanov says. "In civilized countries, any political decision is reached through the parliament, a party, elections, and NGOs. Here, the system is based on family relations. [Aliev's] statement criticizing his father-in-law, the president, sounds very political, because here politics is the family."
Shooting Star?
Aliev claims to have told Nazarbaev "a few months ago" that he "had decided to run for the presidency in the next elections in 2012." Aliev says that shortly after that conversation, he was accused of abducting senior managers of Nurbank, a mid-sized Kazakh bank that Aliev is said to control.
In late May, Kazakh authorities suspended two major media outlets believed to be controlled by Aliev and his wife, Darigha Nazarbaeva -- KTK television and the weekly publication "Karavan."
Nazarbaeva is a powerful figure in her own right in Kazakhstan (ITAR-TASS file photo)