The widow of Kazakh political exile Rakhat Aliyev, the millionaire who took refuge in Malta for years, yesterday said it was “out of the question” that her husband had committed suicide.

“For me, it is out of the question that Rakhat voluntarily ended his own life. He loved his family far too much to do so, and would never have deserted us,” she said.

She spoke for the first time yesterday through a letter that was read out in Vienna, where Mr Aliyev’s lawyers held a press conference in which they too argued there were suspicious circumstances surrounding his death.

The former son-in-law and sworn enemy of Kazakh dictator Nursultan Nazarbayev was found dead last Tuesday in the bathroom of the single prison cell in Vienna, where he was awaiting trial for the murder of two bankers in Kazakhstan.

On that day, he was due to testify against two former cellmates accused of blackmailing him with the threat of having him killed in a way that would look like suicide.

A post-mortem on Mr Aliyev’s body concluded that he had likely committed suicide, even though traces of barbiturates – illegal sedatives – were found.

However, his lawyer, Klaus Ainedter, yesterday criticised the fact that the physician who carried out the autopsy was the same one who was to appear as the prosecution’s witness in the murder trial.

“I don’t know about you but I find this incredible,” he said, pointing out that one of his team’s defence lines in the trial was precisely that the prosecution relied on the medical forensics carried out by Kazakh police authorities rather than carry out their own research. In light of the defence’s claims, Austrian authorities have now ordered a second autopsy that will be carried out by Swiss forensic specialists.

Dr Ainedter criticised the Viennese prison authorities for declaring the death a suicide just two hours after the body was found, and an hour before the forensic team had even started their work.

He raised further questions, such as the fact that the body had no signs that Mr Aliyev struggled during the choking – a natural human instinctive reaction in suicide cases.

The story of how the once all powerful Rakhat Aliyev found himself in that prison cell is a serpentine one.

He experienced a meteoric rise to power and fortune after he married the daughter of Kazakstan’s ruling dictator.

He was appointed deputy chairman of Kazakhstan’s post-Soviet secret service and became the country’s first deputy foreign minister, and simultaneously had a sugar and media empire that made him a multimillionaire.

Things started going pear-shaped in 2007, when he fell out with his powerful father-in-law after declaring himself a presidential candidate.

At around the same time, Mr Nazarbayev signed constitutional amendments effectively making him a president for life.

At first Mr Aliyev was pushed aside and appointed Kazakh Ambassador to Austria, however, shortly afterwards he became embroiled in a controversy over the disappearance of two former executives of a Kazakh bank, which he owned in part at the time.

Austrian authorities refused to extradite him based on Kazakhstan’s human rights record.

He was found guilty in absentia and sentenced to 40 years in jail. However, he remained on the run and eventually sought refuge in Malta, which does not have an extradition arrangement with Kazakhstan.

However, he left Malta soon after a rare interview with this newspaper in July 2013, fearing for his life and claiming that the country’s secret service had established a network in Malta with a mission to “kidnap or kill” him.

Then, last May, Austrian authorities agreed to hear the murder trial in Vienna and issued an arrest warrant. He gave himself up to Austrian authorities in June, saying he was confident the process would help clear his name.