MI5 records reveal gerbil spycatcher plan

The gerbils were to be trained to help smell a rat

Security Serivce MI5 once planned to recruit a team of specially-trained gerbils as a secret weapon to sniff out spies, it has been revealed.

The animals were to help interrogate suspects because they could use their acute sense of smell to detect a rise in adrenalin - the chemical released in sweat when people feel under stress.

The security service's director general Sir Stephen Lander revealed the plan was considered during the 1970s when he spoke at the launch of a new spy exhibition in London.

But MI5 dropped the plans after it was discovered the gerbils could not tell the difference between terrorists and passengers who were scared of flying.

Israeli idea

MI5 archives contain a complete volume on the idea, which would have played a key part in interrogating suspected spies.

Sir Stephen said research for the Royal Canadian Mounted Police had uncovered the gerbil's skill and the Israelis had first put it to the test, he said.

They had kept the rodents in cages next to security check areas in Tel Aviv airport.

Sir Stephen made the revelation in a rare public speech

Carefully placed fans wafted the smell of a suspect's hands towards the animals' nostrils.

The gerbils were trained to press a lever if they detected rises in adrenalin, but it was then found they could not discern between suspects and frightened passengers.

Sir Stephen made the revelation at the Missing Dimension conference at the Public Record Office (PRO) in Kew, London.

Spies on show

His rare public speech marked the PRO's new Shaken Not Stirred exhibition on espionage.

The show includes exhibits on a number of spies, including Mata Hari.

A small team of retired agents is working through some 400,000 files produced by the service, deciding which are safe to put on public view.

Material from the 1920s and 1930s are due to be declassified later this year but the team are not expected to finish work on the period up to the end of the World War II for another three to four years.

Exploding rats

The gerbil plan is not the first time British agents have considered using rodents.

Exploding rats were part of an armoury of James Bond-style gadgets used by agents in the World War II, according to records released two years ago.

It also emerged earlier this year that MI5 was planning to use more conventional but still controversial US-style lie detectors.