A FORMER MI5 officer who helped to smash the Portland spy ring in the 1960s has died aged 88.

Charles Elwell played a crucial part in exposing five KGB agents who were leaking secret information to Moscow from the island.

He was a master spycatcher and a colourful officer who made his name by targeting Russian agents during the Cold War.

Mr Elwell achieved his greatest success when the KGB posed the gravest threat to Britain by trying to acquire military and technology secrets.

The Portland spy ring was led by Konon Molody who posed as Gordon Lonsdale, a Canadian running a jukebox leasing firm.

Mr Elwell's role in the unmasking began when a Russian mole called Sniper told the CIA secrets were reaching Moscow from Portland.

MI5 were informed the information was coming from the Admiralty Underwater Weapons Establishment on the island.

Officers suspected the spy was Harry Houghton, a clerk working at the secret facility who was living above his means.

He had accepted an offer from Lonsdale, posing as a US naval commander, who promised him thousands of pounds for giving information to US intelligence.

Houghton, who lived in Meadow View Road in Weymouth, had a lover called Ethel Gee, who also worked at the Portland base, and she too sold secrets.

The couple regularly met at The Elm Tree Inn in Langton Herring but their heavy drinking and spending attracted police attention.

Mr Elwell was named case officer and his team began unravelling the scale of the spy plot.

Houghton and Gee travelled to London every Saturday where they met a man - Lonsdale - and handed over parcels.

Lonsdale was followed and tracked to a Ruislip bungalow belonging to Peter and Helen Kroger, a New Zealand couple who ran a small bookshop.

The Krogers, wanted by the FBI in connection with a nuclear espionage case, were also part of the ring and their home was full of espionage equipment.

Film and photographs of secret documents were smuggled out of the Portland base by Houghton and transmitted to Moscow in the form of microdots hidden in antique books.

His Weymouth home and Gee's home in Hambro Road, Portland, were searched and revealed plenty of evidence of their guilt.

Lonsdale was jailed for 25 years and the Krogers were given 20-year sentences.

Houghton and Gee were sent to prison for 15 years.

Charles John Lister Elwell won praise from the Lord Chief Justice for his investigation of the case and was appointed OBE in 1961.

Mr Elwell was born in 1919 and read modern languages at Oxford before joining the Royal Navy in 1940.

He served in motor gunboats on the south coast, which landed agents in occupied Europe.

Mr Elwell was taken prisoner in 1942 and, after a botched escape attempt, was sent to Colditz for the rest of the Second World War.

He was demobilised in 1945 and joined MI5 four years later before marrying security service colleague Ann Glass.

Mr Elwell spent his last five years at MI5 in the counter-subversion branch before retiring in 1979,.

He then took up soft fruit farming.

His wife died in 1996. He is survived by their two sons and two daughters.