LONDON (AFP) - A chemical linked to a rare poison was found in the body of a wealthy Russian businessman who died suddenly in Britain three years ago, a newspaper report said Tuesday.
Alexander Perepilichny was helping an investigation into an alleged money laundering scheme involving Russian tax officials at the time of his death, The Times added.
The 44-year-old collapsed outside his mansion on a luxury private estate on the outskirts of Weybridge in Surrey, near London, on Nov 10, 2012.
Bob Moxon Browne, a lawyer for Perepilichny's life insurance company, told a pre-inquest hearing into the death that test results had revealed a chemical that could be traced to the poison Gelsemium, The Times reported.
"Once you have knocked out man-made analogues then you are bound to conclude Mr Perepilichny ingested Gelsemium on the day of his death," the lawyer said.
"Then, given that it only grows in China and is a known weapon of assassination by Chinese and Russian contract killers, why was it in his stomach?"
Contacted by AFP, the lawyer and the Surrey coroner leading the inquest declined to comment.
A spokeswoman for the Royal Botanic Gardens in London told AFP the institution "has supplied its expertise in plant chemistry to assist the coroner's inquest".
But she declined to comment further "due to the sensitive nature of this work" until the inquest is completed, as expected later this year.
Gelsemium elegans is the most toxic variety of the gelsemium plant and only grows in Asia.
It is also known as "heartbreak grass" and early symptoms of ingestion include dizziness, nausea and convulsions.
Higher doses can cause paralysis of the spinal cord, a loss of muscular power and eventually asphyxia.
According to British press reports at the time of his death, Perepilichny was providing evidence on the death of anti-corruption lawyer Sergei Magnitsky in a Russian jail in 2009.
Magnitsky died at the age of 37 after being held in a notoriously squalid Russian prison during a fraud probe against his client, US investment firm Hermitage Capital.
Before he was detained, the lawyer claimed to have uncovered a scheme used by police officials to reclaim about US$235 million (S$311 million) in taxes paid by Hermitage Capital, once Russia's largest Western investment fund.
But instead officials charged Magnitsky with fraud and put him in jail.