Leaflet at Heart of McDonald's Libel Case in England Written by Police Spy

Went undercover as environmental activist and embroiled group in massive lawsuit

An undercover police officer posing for years as an environmental activist co-wrote a libellous leaflet that was highly critical of McDonald's, and which led to the longest civil trial in English history, costing the fast-food giant millions of pounds in fees.

The true identity of one of the authors of the "McLibel leaflet" is Bob Lambert, a police officer who used the alias Bob Robinson in his five years infiltrating the London Greenpeace group , is revealed in a new book about undercover policing of protest, published next week.

McDonald's famously sued two penniless green campaigners over the roughly typed leaflet, in a landmark three-year high court case, that was widely believed to have been a public relations disaster for the corporation. Ultimately the company won the libel battle it need never have fought, having spent expensively on lawyers.