The co-founder of social networking site Ask.fm told ITV News he believes David Cameron "did not have all the information about the case" when he urged parents to boycott "vile sites" following the death of cyberbullying victim Hannah Smith.
Klavs Sinka said he believed the Prime Minister "hadn't really researched" the case before he made his comments.
He continued, "He was probably caught on the street in an interview similar to this and made a comment without having the full information about this case."
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Nearly 38,000 runners will hope to complete Sunday's London Marathon making it the biggest event in its 35-year history.
Rain across central Britain with longer, intense downpours with thunder in places this evening. A lucky few will stay sunny and dry.
Planning on going to the London Marathon tomorrow? Read our handy guide first!