A businessman accused of defrauding the Russian military has been raped and tortured to death inside his jail cell while awaiting trial.

Valery Pshenichny, 56, was accused of embezzling 100 million rubles (£1.3 million) while carrying out work on the construction and repair of submarines.

The entrepreneur, who has been compared to Elon Musk, was found hanging inside a St. Petersburg jail cell in February three weeks after his arrest.

Valery Pshenichny was raped before he died, a postmortem examination has revealed

Pshenichny developed a unique modeling technology for construction and repair of Russia's Kilo - class submarines. File picture of Kilo - class submarine Rostov-on-Don

According to the Novaya Gazeta newspaper, a post mortem examination has now revealed that Pshenichny died from neck trauma and asphyxiation, and had been raped before his death

'Electric shock burns from a hot-water boiler cord were found in his mouth. Lacerations and stab wounds on his body. A broken spine. Simply put, he was tortured,' the newspaper listed expert findings as saying.

It added that Pshenichny, who had been in custody for several months, did not take his own life and a criminal case into incitement to suicide has been opened.

He had developed a unique modeling technology for construction and repair of the improved Kilo-class submarine, known as Project 636 Varshavyanka in Russia.

Pshenichny was found dead in St. Petersburg jail cell while awaiting trial

Pshenichny initially suspected his business partner Andrei Petrov of theft in 2016.

But Petrov testified that Pshenichny and another associate had conspired to inflate the cost of the contract.

'My husband and I were together for 40 years. I've never met such a smart, bright, strong, positive person,' Novaya Gazeta quoted his wife, Natalya, as saying.

'He was confident in himself, in his position, he knew that he was innocent and was not afraid of anything,'

The director of the Agora international human rights organization Pavel Chikov said Pshenichny's last words were: 'Everyone betrayed me.'