DISTURBING reminders of West Dorset's link with murdered Bulgarian dissident Georgi Markhov were revived this week with the discovery of a suspected terrorist poison-making factory in London.

Markhov, who is buried at Whitchurch Canonicorum, was killed when a pellet containing the deadly toxin ricin was injected into his leg through the tip of a sharpened umbrella in 1978. It is the same poison found by anti terrorist police in their raid on the flat in North London at the weekend.

Yesterday (Thursday) Markhov's mother-in-law Alice Dilke, who lives at in Whitchurch, said renewed media interest in the assassination had brought back distressing memories

"It is very upsetting because it happened over 20 years ago and it is time we drew a line under this. It is very distressing for my daughter and granddaughter," she told The News.

Markhov, a leading broadcaster and playwright received the lethal injection while waiting at a bus stop on Waterloo Bridge in London. After feeling a sharp pain in his right thigh he turned to see a man pick up an umbrella, apologise and vanish into the crowd. That night Markhov fell into a fever and he died three days later. He was 49.

A post mortem examination uncovered a platinum and iridium sphere just 1.5mm in diameter in the wound on Markhov's thigh. The ball had two holes bored into it, enough to hold just 0.28 cubic mm of liquid. Experts said because of the tiny dose and distinctive symptoms the poison could only have been ricin. Tests ordered by the coroner showed that an injection of the same dose of ricin was fatal for a fully grown pig.

Markhov had close links with Whitchurch Canonicorum after marrying Annabel Dilke - the daughter of Christopher and Alice Dilke - in 1975.

The couple set up home in Clapham but their daughter Alexandra Raina was baptised in Whitchurch's 12th century church of St Candida and the Holy Cross in 1977.

Armed Special Branch officers mingled with mourners during his funeral in the village in October 1978, which was attended by several other Bulgarian defectors - who were also putting their lives at risk by appearing in public. Afterwards Mrs Dilke claimed the KGB had a hand in her son-in-law's assassination and said it was almost certain the ricin used came from Russia.

In 1991 Bulgarian president Zhelyu Zhelev visited the cemetery at Whitchurch to lay a wreath on Markhov's grave and he pledged to find the truth about who killed him.

Later it was established that the Bulgarian secret service and the KGB were involved. Two senior members of the secret police were eventually jailed for their part in covering up the murder by shredding files in 1990. The case was finally closed three years ago.

*This week seven men were being questioned after anti-terrorist police raided a one-bedroom flat in Wood Green, North London, and discovered traces of the deadly ricin as well as the ingredients and equipment for making it. It is feared that other suspects with quantities of ricin could still be at large.

GPs and hospitals across the UK have been alerted to look out for anyone with signs of ricin poisoning.

Only minute amounts of the poison, which can be administered by injection, ingestion, inhalation or simply by physical contact, are needed to kill.

There is no known antidote to ricin, which experts say has the potential to be used as a bio-terror agent or weapon of mass destruction.

But experts say ricin is most suited to being used, possibly through an aerosol, in an assassination attempt on a leading public figure rather than a mass attack on a busy civilian target such as the London Underground.

It could also be smeared somewhere where many people would touch it.

Plans by Osama bin Laden's al Qaida terror network to produce ricin were found in the Afghan capital of Kabul in November 2001.