Christian Skjaerstad is a neighbour and childhood friend of Alexander and Thomas Hunter.
He says the 21-year-old's were normal boys, and was shocked to hear about the scam.
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Sandiford, a former legal secretary originally from Redcar, was convicted of drug smuggling offences and sentenced to death in 2013.
Durham Crown Court heard that one of the male victims suffered a triple-fractured jaw, while left lying in the gutter, unconscious.