Kazakhstan's president has been accused by his son-in-law of trying to silence him after he declared his intention to run for the presidency.

Rakhat Aliyev, the husband of Nursultan Nazarbayev's daughter Dariga, has fallen out with the president and has accused him of rolling back democracy in the Central Asian nation.

"A few months ago I told Nursultan Abishevich [Nazarbayev] that I had decided to run for the presidency in the next elections in 2012," Aliyev said in a statement on the website of the Kazakhstan Today news agency which he controls.

"Shortly after that conversation the Nurbank case happened.

"This hastily organised case is truly 'important'. Its 'importance' lies in the attempt to remove me from the political process in the country," he said.

President for life

Nazarbayev, in power in the oil-rich Central Asian state since 1989, this week signed constitutional amendments allowing him theoretically to stay in office for life. His current presidential term ends in 2012.

"I think the effective usurpation of the [presidential] post by one person, turning elections into a farce for foreign monitors, a gradual rollback of democratic achievements, are not helping our country, to say the least," Aliyev said.

Nazarbayev's son-in-law was sent to the Austrian capital, Vienna, as ambassador this year in what analysts called "luxury exile".

The authorities have also taken his KTK television channel off the air and closed his Karavan newspaper for three months for violations of Kazakh law - a move criticised by the US embassy in Kazakhstan.

Aliyev has called the Nurbank case and the seizure of his media assets "absurd" and "illegal".

Despite his current rift with the president, Aliyev is unlikely to get much support from the political opposition in Kazakhstan, led by the Real Ak Zhol party, which accuses both him and Nazarbayev of corruption and nepotism.