The son of a Russian defector who died in Wiltshire 17 years ago has called on the British authorities to investigate his death amid allegations

he was killed by KGB agents.

Vladimir Pasechnik was a Soviet micro-biologist who defected to Britain in 1989 when he warned that Russia's germ warfare programme was 10 times greater than thought.

He went on to work at the microbiological research centre at Porton Down, near Salisbury, Wilts, and died in 2001 aged 64.

While Pasechnik's official cause of death was given as a stroke, his son, Nikita, who lives in West Bay, suspected foul play and espionage activities were behind it.

And following the apparent poisoning of Russian spy Sergei Skripal and his daughter Yulia in Salisbury last Sunday, Mr Pasechnik said he is even more certain.

Despite voicing concerns that speaking out might put his own life in danger, the 53-year-old said he is in 'no doubt' that Mr Skripal was targeted by the Russian authorities - like his own father.

He has called for his father's death to be investigated after MP Yvette Cooper asked in Parliament for Home Secretary Amber Rudd to launch an inquiry into 14 suspicious deaths in recent years which are potentially connected to Russian intelligence services.

His father's death is not listed among these cases, which Mr Pascehnik believes needs to be addressed.

And he slammed Foreign Secretary Boris Johnson's threat that British dignitaries and officials may boycott the football World Cup in Russia this summer as 'weak', saying Putin 'would be laughing at him'.

Mr Pasechnik, who lives in Bridport, Dorset, and works as an IT specialist, said: "Of course it is important that every case is investigated, including my father's.

"My father ruined the whole industry of biological weapons in Russia when he escaped to the UK and told the government and Margaret Thatcher (about Russia's programme).

"My father was always scared and told me the KGB might kill him.

"He understood how serious the threat to him was and told me several times the story of a Bulgarian diplomat who was killed by an umbrella.

"Officially his cause of death was a stroke but I spoke to doctors and they said his brain was severely damaged in different areas and they had never seen a stroke like it - it was as if he had several strokes simultaneously.

"They didn't understand the reason for the stroke.

"I spoke to specialists in different countries and they confirmed certain chemical substances could cause a stroke by causing the blood to go thick and creating a clot.

"I see similarities between my father and what has happened in Salisbury.

"My father was at home and he had a severe headache and felt dizzy.

"He took painkillers and tried to drive to his office but turned back then smashed his side mirror driving onto the garage before collapsing in the home.

"My mother was there and they rushed him to hospital but he died several weeks later.

"There was never a proper investigation into his death.

"It is very difficult to say how or where it happened but I believe my father was poisoned.

"What happened to my father has happened to many Russians who opposed Putin like Litvenenko and Berezovsky.

"I fear Putin myself but I have to speak out because he must be stopped.

"The Russian authorities are very dangerous, they are very arrogant and they believe they can threaten anybody.

"I was disappointed with Boris Johnson's response that they may not send dignitaries to the World Cup.

"Putin will be laughing at such a weak response."