A BUSINESSMAN who threatened a poison gas ''blitz'' on Cyprus was

yesterday found guilty of trying to use the elaborate hoax to extort #9m

from the island's Government.

Jailing 38-year-old British-born Panos Koupparis for five years, Old

Bailey Judge Mr Justice Macpherson said his blackmail attempt had caused

''prolonged and marked apprehension'' to the authorities.

Koupparis, of Fenwick Road, Peckham, south London, sent a blackmail

demand to Cyprus President Spyros Kyprianou in March, 1987, warning that

unless the cash was handed over generators concealed on the island would

begin pumping out poisonous dioxine gas and destroy life for ''centuries

to come''.

Koupparis styled himself ''Commander Nemo,'' head of a terror

organisation called ''Force Majeure'' -- like the gas, a figment of his

imagination, the court was told.

When the Cyprus Government failed to respond immediately to the

demand, Koupparis, who deals in surveillance equipment to Middle Eastern

countries, made scrambled telephone calls from London posing as

''Colonel Digsby of British Military Intelligence.''

He advised that Force Majeure was a serious threat and that the cash

should be handed over. Koupparis was eventually arrested by

anti-terrorist squad detectives as he left the London office of the High

Commissioner for Cyprus, Mr Tassos Panayides, following a desperate last

attempt to earn some cash from his deceit.

Using a false name, Koupparis had just collected what he thought was

#25,000 -- in fact it was fake money -- after ''volunteering'' to help

the Cyprus Government locate the non-existant gas generators.

Koupparis, who told the jury he saw himself as a future president of

Cyprus, maintained he had been living in a ''fantasy world'' because of

drugs prescribed for depression.