However, Yassin Salhi, 35, a father of three, had not been actively monitored by security officers since 2008 say French authorities.
Protestors chain themselves to posts to stop building of farm in Somme which they liken to 'factory farming' and say will destroy the countryside.
It is known as the farm of a thousand cows. Work has begun to build a huge dairy farm in northern France that will produce up to 8.5 million litres of milk a year and run a methane power plant. Supporters of the intensive farming project say it is the most efficient way to farm given the level of Europe-wide competition and the low prices that smaller-scale dairy farmers get for their milk. Opponents – who staged a demonstration at the weekend - say it is bad for the environment and for local people. Jade Lindgaard reports on a clash of two farming cultures.