Kazakhstan has sent a team of prosecutors to Vienna to try to arrest the son-in-law of the Kazakh president, as a family feud deepens.
President Nazarbayev has a stormy relationship with his son-in-law
Rakhat Aliyev, who is married to President Nursultan Nazarbayev's eldest daughter, was sacked as ambassador to Austria on Saturday.
He is accused by Kazakh authorities of masterminding the kidnapping of two senior bankers.
Mr Aliyev says the case is aimed at silencing his political ambition.
A spokesman for the Kazakh Interior Ministry told a news briefing on Monday: "The prosecutor's office has issued a warrant for [Rakhat Aliyev's] arrest. A special group led by the deputy prosecutor-general and Interpol representatives in Kazakhstan have left for Vienna."
Mr Aliyev maintains that the charge that he was involved in the kidnapping of two former officials of the Kazakh bank Nurbank are fabricated.
"Several months ago I told Nursultan [Nazarbayev] that I had taken the decision to stand for the presidency at the next elections in 2012... Soon after this conversation the Nurbank robbery saga began," he said on Saturday.
He has told the BBC he wants to bring reform to Kazakhstan.
"We should create a democratic civil society in line with European standards," Mr Aliyev said at the weekend.
But the BBC's correspondent in Kazakhstan, Natalia Antelava, says Mr Aliyev is a highly controversial figure who has been involved in many political scandals and has wide-ranging business interests.
This family feud is about money and power rather than democratic values, our correspondent says, but in Kazakhstan, politics is a family affair, and that is why the president's relationship with his son-in-law could affect not only political stability, but also billions of dollars worth of Western investment.
President Nazarbayev has been in office for 17 years. Last week he strengthened his rule by changing the law to allow him to run for the presidency as many times as he likes.