A spy who had infiltrated into an anti-aviation group has been exposed after a series of errors aroused suspicions of a dual identity.

After graduating from Oxford last year, Toby Kendall joined Plane Stupid, a British direct-action pressure group 'taking action against airport expansion and aviation's climate impact'.

He told the activists that his name was Ken Tobias and said that he was deeply concerned by the impact of the aviation industry on climate change.

His identity came under question after members realized Kendall always kept a low profile at rallies and group events, including a time he dressed up as a penguin in a certain protest.

Plane Stupid began a mole hunt, feeding him false information on a fake action and discovered two days later that security at airports around the UK had been alerted.

After discovering his real name the group identified him as working for C2i International, a counter-intelligence company run by former special forces officers.

Since being exposed, Kendall failed to return calls and appears to have gone to ground.

MT/BGH