Vlada Dzyuba, 14, attracted worldwide headlines after her sudden death in Shanghai which was variously blamed on exhaustion, meningitis or septicaemia

A top Russian teenage catwalk star who died suddenly on a gruelling three month modelling-trip to China may have been murdered, according to sensational findings from her autopsy in Moscow.

Vlada Dzyuba, 14, attracted worldwide headlines after her sudden death in Shanghai which was variously blamed on exhaustion, meningitis or septicaemia .

Her case was seen as symbolising the exploitation of underage models by the fashion industry, and she worked in China without medical insurance which may have delayed her receiving treatment when she became ill.

But initial findings from an autopsy after her body was flown back to Russia indicate there are traces of a mystery 'biological poison'.

'Vlada could have been bitten by a mortally poisonous insect, she could have eaten something, or been deliberately poisoned,' reported news outlet Life, citing law enforcement sources.

The reports raise the horrific possibility of the popular model being targeted possibly by a rival.

However, it is clear additional tests are needed.

Her case was seen as symbolising the exploitation of underage models by the fashion industry, and she worked in China without medical insurance which may have delayed her receiving treatment when she became ill

'Vlada could have been bitten by a mortally poisonous insect, she could have eaten something, or been deliberately poisoned,' reported news outlet Life, citing law enforcement sources

The reports raise the horrific possibility of the popular model being targeted possibly by a rival

The exact 'organic poison' is not yet identified.

'Experts did not find its origin yet, but it is clear that it wasn't a simple infection that killed her,' reported news outlet Mash.

The Chinese hospital where she died said she suffered blood poisoning 'with multiple visceral organs damaged, liver dysfunction and renal insufficiency'.

It did not raise the possibility she could have been deliberately poisoned or bitten by a lethal insect.

A criminal case was opened into her death last month by the Russian Investigative Committee, seen as similar to the FBI.

As yet, there has been no official comment from the Russian authorities on the latest reports.

Vlada died after falling ill as she completed a 13-hour modelling assignment.

She was not sent to a doctor but instead told to take a 185-mile rail journey back to Shanghai and rest.

Vlada (right) had complained by phone to her mother Oksana (left) - 4,000 miles away in Russia - of acute tiredness. In her final conversation with her mother, Vlada said: 'Mama, I am so tired. I so much want to sleep'

The Chinese hospital where she died said she suffered blood poisoning 'with multiple visceral organs damaged, liver dysfunction and renal insufficiency'

Three modelling agencies linked to the 14-year-old - one of many underage Russian models recruited to Asian catwalks, especially China - have all denied any responsibility for her death

Russian investigators have been interrogating her parents, two Russian model agencies, and seeking assistance from the Chinese authorities. Pictured: Antonida Gorbanyuk and a younger Vlada

Soon afterwards her condition worsened with a temperature above 102F and she was sent to hospital where she died less than two days later.

Vlada had complained by phone to her mother Oksana - 4,000 miles away in Russia - of acute tiredness.

In her final conversation with her mother, Vlada said: 'Mama, I am so tired. I so much want to sleep.'

Vlada had complained by phone to her mother Oksana - 4,000 miles away in Russia - of acute tiredness

A 'death by negligence' criminal probe had been opened in Moscow.

The Investigative Committee met most of the costs of returning her body.

Russian investigators have been interrogating her parents, two Russian model agencies, and seeking assistance from the Chinese authorities.

Three modelling agencies linked to the 14-year-old - one of many underage Russian models recruited to Asian catwalks, especially China - have all denied any responsibility for her death.

Shanghai agency ESEE earlier denied that Vlada's death was 'avoidable', saying her illness was 'too serious', reported The Siberian Times.

The Russian modelling boss who negotiated her contract in China has not commented on why she had no medical insurance.

Her contract specified this was the responsibility of the model herself or her family or representatives.

Vlada was seen as popular in China and took part in the Shanghai Fashion Week.

An increasing number of underage Russian models are in demand in China.