Anders Breivik made internet contact with the EDL just months before carrying out his killing spree. In other online postings, he claims to have had discussions with members as long ago as 2009.
Channel 4 News has also learned that:
• Breivik posted anti-Muslim messages on the German Defence League's website in February
• Breivik claimed Norwegian police had taken down his NDL website in the same month and placed him and others on a "danger list"
• Large sections of his manifesto were made up of comments posted on a politics website two years ago
• One of the chilling comments on the politics website reads: 'It is children... who end up as victims'
The news that Breivik was in contact with the EDL earlier this year comes as the group's leader retracted a denial that the group had ever had contact with the man behind the killing of at least 76 people in a bomb blast and a series of shootings in Norway on Friday.
Stephen Lennon said: "It could turn out that one of our members met with him but at this point we're not turning anything up."
Anti-fascist organisation Searchlight has trawled through the English Defence League's online forums and claims that Breivik used the pseudonym "Sigurd Jorsalfare", a 12th century King of Norway who led one of the Crusades, when he exchanged messages of support with members in March.
Breivik's introductory message reads: "Hello to you all good English men and women, just wanted to say that you're a blessing to all in Europe, in these dark times all of Europe are looking to you in surch (sic) of inspiration, courage and even hope that we might turn this evil trend with islamisation all across our continent. Well, just wanted to say keep up the good work it's good to see others that care about their country and heritage."
The post received positive replies from three EDL members, one of whom exchanged messages with Breivik about the perceived problems facing both countries.
The 32-year-old admitted that he had been in England in the past few years, sarcastically noting that "me and a friend walked down to the football stadium of Bradford, real 'nice' neighborhood, same thing in the suburbs of London".
Breivik then added that he was planning to travel to Britain to attend an EDL demo, saying "(it would be) nice with a Norwegian flag alongside with union jack or the English flag… it's our common struggle against the islamofacists (sic)."
And days before, Breivik was also active on the German Defence League's forum, Channel 4 News has discovered.
Using the same moniker, he wrote "...For anyone who might be intrested (sic) in our common struggle but further north, our site is http://norwegiandefenceleague.wordpress.com/...keep fighting on, we cannot surrender Europe to these crazy islamists..."
The NDL has distanced itself from Breivik but had not responded to a request for a comment about the comments at the time of publication.
It is often the children of the boundless(ly) naive and Marxist kids who end up as victims - Anders Breivik
Perhaps the most concerning claims made in Breivik's postings on the Defence Leagues' sites is that Norwegian police shut down the NDL website and blacklisted its members.
"I was (a member) but the site has been put down now…there was to be a demo in Oslo on the 26 of February, but after the police security service put us on the 'danger-list' the internet site was sadly shut down," he wrote in a post.
It has also emerged that much of Breivik’s near-1,500-page anti-Muslim manifesto was a compilation of comments he had posted between 2009-10 on a Norwegian political website.
"It is often the children of the boundless(ly) naive and Marxist kids who end up as victims," he wrote on Document.no in 2009, asking like-minded people to contact him on his email address "year2083", the title of his manifesto.
Breivik's manifesto claim that he had discussed strategies with EDL members also appears on the site in a post left in 2009, suggesting a longer association than previously reported.
On Monday, Channel 4 News revealed the extent of the EDL's influence over the NDL. In March, Hel Gower, a leading figure in the EDL hierarchy, posted a comment on the NDL's Facebook page, saying her group had ruled on problems caused by the latter's leadership vacuum and appointed an interim head.
There are currently about 50 police officers from around Europe assigned to a specialist unit in The Hague attempting to piece together Breivik's links to far-right groups in the UK and the continent.
Please wait while this video loads. If it doesn't load after a few seconds you may need to have Adobe Flash installed.