Kazakh non-government groups expressed concern in Vienna on Thursday about human rights in their country, which is to take over the chairmanship of the OSCE next year.
Human rights violations have "nearly reached the level it used to be in the former Soviet Union," said Daniyar Kanafin, an Almaty-based lawyer who represents Mukhtar Dzhakishev, a former chief of state nuclear firm Kazatomprom, who was arrested on May 21 on embezzlement charges.
Kanafin said that, as Dzakishev's lawyer, he had been denied access to the case against his client, with authorities citing "national security" reasons.
"Everybody has a right to get a fair trial. This case raises the question on how people are protected and to what extent," said Yevgeniy Zhovtis, director of the Kazakhstan International Bureau for Human Rights and Rule of Law.
There was "clearly a political motivation" behind the case, he said. "We are concerned by the development making the situation worse than it was five or 10 years ago."
In recent weeks, President Nursultan Nazarbayev, who has ruled Kazakhstan since the collapse of the Soviet Union in 1991, has embarked on a purge of leading political and adminstrative figures.
Defence minister Danial Akhmetov was sacked and former nuclear chief Dzhakishev and the former head of Kazakhstan's biggest bank BTA, Mukhtar Ablyazov, have been accused of stealing tens of billions of dollars in state and investor funds.
Dzhakishev is now in prison while Ablyazov -- also a former prime minister -- fled abroad.
Kanafin said critical lawyers were subjected to pressure and even threatened to have their licences withdrawn.
The non government groups have compiled a 70-page document on human rights violations in Kazakhstan which would be handed to the Organisation for Security and Co-operation in Europe on Thursday.
"With less than six months to the Kazakh presidency, it's time the government brings legislation in compliance with the OSCE commitments," said Vera Tkachenko of the LPRC group.