Breivik reportedly met leaders of the EDL in March last year when he came to London for the visit of Geert Wilders, the Dutch right-wing politician.
Daryl Hobson, who organises EDL demonstrations, said Breivik had met members of the group.
Hobson said in an online posting: "He had about 150 EDL on his list ... bar one or two doubt the rest of us ever met him, altho [sic] he did come over for one of our demo [sic] in 2010 ... but what he did was wrong. RIP to all who died as a result of his actions."
Another senior member of the EDL said Breivik had been in regular contact with its members via Facebook, and had a "hypnotic" effect on them, the Daily Telegraph reported today.
Scotland Yard was investigating Breivik`s claims that he began his deadly "crusade" after being recruited to a secret society in London, and that he was guided by an English "mentor."
Prime Minister David Cameron said Breivik`s claims were being taken "extremely seriously."
Breivik wrote of having strong links with the EDL, saying he had met its leaders and had 600 EDL members as Facebook friends.
Another senior member of the EDL, who spoke to The Daily Telegraph on condition of anonymity, said he understood Breivik had met EDL leaders when he came to Britain to hear Wilders speak in London last year.
He said: "I spoke to him a few times on Facebook and he is extremely intelligent and articulate and very affable.
"He is someone who can project himself very well and I presume there would be those within the EDL who would be quite taken by that. It`s like Hitler, people said he was hypnotic.
This guy had the same sort of effect."
Breivik compiled a 1,518-page document, written in English under his Anglicised name Andrew Berwick, in which he made repeated references to his British links and in particular his links to the EDL.
He wrote: "I used to have more than 600 EDL members as Facebook friends and have spoken with tens of EDL members and leaders. In fact, I was one of the individuals who supplied them with processed ideological material (including rhetorical strategies) in the very beginning."
The EDL had earlier stated on its website that it had no links to Breivik.