VIENNA (Reuters) - Austria has asked Switzerland to carry out an autopsy on Rakhat Aliyev, a Kazakh dissident found hanged in an Austrian prison last week, to dispel any suggestions of a cover up after a first post mortem found traces of sedatives.

The authorities say Aliyev committed suicide and there was no indication of the involvement of any third party in the death, but Aliyev's lawyers have contested the official line on how their client died.