The inquest in London heard evidence on Friday, April 13, about how Surrey Police used an untrained civilian to translate the contents of Mr. Perepilichnyy's computer and then managed to lose the hard drive.
Detective Superintendent Ian Pollard insisted it had been "appropriate" to use Ekaterina Clarke-O'Connell, a civilian who worked in Thames Valley Police's HR department to seek out and translate relevant material on Mr. Perepilichnyy's computer.
Rather than giving the task to an MI5 or MI6 agent or to a police officer he assigned the job to Ms. Clarke-O'Connell, a native Russian speaker who moved to England in 2002.
Giving evidence, Ms. Clarke-O'Connell admitted she had no police or investigative training and the Perepilichnyy case was the first criminal investigation she had ever worked on.
The inquest at the Old Bailey heard she had been asked to look out for certain key words and phrases and any indication Mr. Perepilichnyy was being threatened or had health concerns.
Reference to US$500 Mln Payment on Computer
She recalled finding a reference on the computer to a payment of "half a billion dollars" to Perepilichnyy around the same time his Swiss bank accounts were frozen by the authorities, in 2012.
But she failed to notice Skype messages which included an attempt to elicit a one million euro bribe or his efforts to negotiate his way out of being prosecuted for a giant fraud perpetuated against Hermitage Capital Management.
Det. Supt. Pollard was also asked by Lucas Fear-Segal, counsel for the company which insured Mr. Perepilichnyy's life, about a document in French which Ms. Clarke O'Connell had flagged up because it contained the name, Quartell, a company which had allegedly been used for money laundering and was being investigated by the authorities in Switzerland.
He admitted the failure to translate or investigate this document was one of the "shortcomings" of the investigation.
Ms. Clarke-O'Connell gave evidence that she found no evidence of any death threats in the last 12 months of Mr. Perepilichnyy's life despite speculation he had been targeted by the Russian mafia, including the "Kluyev group".
'Extortion Attempt' in 2011
There was however three text messages sent by a phone in Belarus in June 2011 which appeared to be an extortion attempt.
"Alexander, if you don't want to go to prison, if you want a safe, free life, you will need to pay 300,000 roubles ($10,000) and you will need to reply with your answer by 2.00 tomorrow," said the first text message.
"Do not make any silly moves. We have everything under control," said a second text message and the third was about how to transfer the money.
The inquest has been told Mr. Perepilichnyy was involved with a company called Hermitage Capital Management, who claimed to be the victims of a $240 million tax fraud in Russia.
Henrietta Hill QC, counsel for Hermitage, repeatedly asked Det. Supt. Pollard if he saw comparisons between Mr. Perepilichnyy's death, that of Alexander Litvinenko and the attack on Sergei Skripal and his daughter Yulia.
Det. Supt. Pollard insisted they were not comparable as there was no evidence of any nerve agent or toxin having caused Mr. Perepilichnyy's death.
He said the hard drive from Mr. Perepilichnyy's computer, which had been handed over by his widow Tatiana, had disappeared from a computer server belonging to the South East Counter Terrorism Unit (SECTU), which comprises Surrey, Sussex, Hampshire and Thames Valley police forces.
Last year, before the inquest was adjourned, Bob Moxon-Browne QC, counsel for Mr. Perepilichnyy's insurers, had demanded to see the original documents from the computer.
Computer Evidence Vanished After 'Server Failure'
But Det. Supt. Pollard had to admit SECTU could not find it, or the back-up version, on their server and had concluded there had been a "server failure".
Fiona Barton QC, for Surrey Police, asked him if any of the evidence which had emerged since 2012 — including documents on Mr. Perepilichnyy's computer — had made any probative difference to his assessment of the cause of death.
"There is nothing in there whatsoever to suggest he was being targeted or the victim of a murder. There was nothing whatsoever," Det. Supt. Pollard replied.
Ms. Barton then went on to criticize Buzzfeed who, she said, had claimed the Perepilichnyy case had been reopened due to events in Salisbury and because of "an investigation by Buzzfeed journalist Jane Bradley."
"Has the case been reopened?" asked Ms. Barton.
"No, it has not," replied Det. Supt. Pollard.
Peter Skelton QC, counsel for the inquest, then read out a statement which had been made by Bill Browder, the American head of Hermitage Capital Management, in which he rounded on Mr. Perepilichnyy's brother-in-law, Rishad Ismagilov.
Was Bill Browder a CIA Agent Known as 'Solomon'?
"Mr. Ismagilov has made a series of spectacular allegations about me, including that I was responsible for the death of Edmond Safra (a banker killed in Monte Carlo in 1999), that I am a CIA and MI6 agent with the codename Solomon and that I was involved in the theft of $4.8 million from the International Monetary Fund," said Mr. Browder.
Mr. Browder said it was telling that Mr. Ismagilov's comments were "exactly the same claims made by the Russian government, which is implicated in the torture and murder of (Hermitage lawyer) Sergei Magnitsky."
Mr. Browder then went on to claim Mr. Ismagilov had been a director of Quartell, a company which had allegedly laundered $10 million.
"Mr. Ismagilov is not being honest about the death of Mr. Perepilichnyy and knows more about the death than he is saying," claimed Mr. Browder.
Perepilichnyy 'Milked Like a Cow'
Earlier Ms. Clarke-O'Connell had recalled how she found a message on his computer from Mr. Perepilichnyy's wife, Tatiana, which referred to Mr. Ismagilov "milking Mr. Perepilichnyy like a cow."
Ms. Hill then asked the coroner to make it clear he did not accept Mr. Ismagilov's statement was "true" because it had not been tested and Mr. Ismagilov had refused to attend the inquest to answer questions.
The coroner, Judge Nicholas Hilliard QC, said he endorsed what she said.
"Mr. Ismagilov's evidence is not accepted and I will look at it with special care," said Judge Hilliard.
Earlier Ms. Hill referred to a list of names of people who had stayed in the Hotel Bristol in Paris at the same time as Mr. Perepilichnyy, only hours before his death and it included a "Nikolai Patrushev" which, she said, was the same name as the FSB head who allegedly ordered the killing of Mr. Litvinenko.
Ms. Hill also said the Russian Embassy had released a press release on April 11 which made a series of allegations about the coroner and the inquest process.
"The representatives of W. Browder's Hermitage Capital Management fund, included in the investigation as an interested person, have been challenging the results of the post-mortem examinations made by the Home Office, which did not find any involvement of a third party or a foul play in A. Perepilichnyy's death," said the Russian embassy statement.
'Attempt to Discredit Widow'
"They tried to discredit Mr Perepilichnyy's widow (by throwing in the theory of a poisoned sorrel soup) and even the police, who were all initially interested persons in the inquest," it added.
"All these circumstances around the inquest into the death of A. Perepilichnyy and the foot-dragging since 2012 clearly indicate that British authorities want to get the most out of this in order to promote the idea of another 'Russian connection' in the case of yet another Russian citizen murdered on the British soil," said the embassy.
Judge Hilliard insisted the inquest was an independent inquiry and he adjourned the case until next month for further inquiries.
"There is a sense in which every inquiry we make can in turn lead to lots of other inquiries and there comes a point where you have to draw the line," said Judge Hilliard.
The coroner also said he had received a letter from the Home Secretary, Amber Rudd, in which she said an investigation into the deaths of 14 Russians in the UK would be concluded by the end of the month.