This video from the USA says about itself:
Meet the FBI Informant Who Organized Neo-Nazi Gathering Attended by Jo Cox Murder Suspect in 2000
22 June 2016
We turn now to look at Thomas Mair, the British man who killed British parliamentarian Jo Cox last week. Mair reportedly yelled out “Britain First” during the attack—a reference to the far-right, anti-immigrant political party of the same name … In court on Friday, Mair gave his name as “Death to traitors, freedom for Britain.” …
More information is coming to light about Mair’s ties to neo-Nazi groups in the United States and Britain. Meanwhile, a former paid FBI informant named Todd Blodgett has revealed he met Thomas Mair at a neo-Nazi gathering that the informant set up in London in 2000. Joining us now is Todd Blodgett, who once worked with several leaders of the far right, including Willis Carto, who founded the Liberty Lobby, and William Pierce, leader of the neo-Nazi National Alliance.