A South African jihadist is accused of having a hidden hand in recruiting a naive teenager who was moulded into a radical advocate of Islamic State and is now serving an 11-year prison sentence in the US. Ali Shukri Amin, of Virginia, was a quiet, polite and intelligent child whose schooling was disrupted by Crohn's disease, according to his teachers.But outside high school the 17-year-old led a double life, calling for the death of "infidels" on a Twitter feed followed by thousands that he called @AmreekiWitness - American witness.The mysterious South African, Uthman Buchs, described as being in his 40s, had "treated Ali like a son", according to a defence submission to a court in Virginia prior to sentencing.story_article_left1Buchs's "apparent interest and paternal caring was [a] primer for his radical ideology", the document said.Buchs was described as one of several "older, online parasites" who made "false promises of identity, purpose and fraternity" to Amin.Using his IS contacts, Amin helped a school friend travel to Syria to join the movement. A cellphone, encrypted thumb drive and documents he organised for the friend's crossing into Syria were intercepted by the FBI.Amin is the youngest person to be prosecuted as an adult in the US for "providing material support to a terrorist organisation".US authorities investigated a ring of pro-IS "radicals" who mentored Amin.They included Buchs, a Finnish man nicknamed Abdullah, and a person in the UK known as Zubair. Abdullah, 20, produced proof of his friendship with Amin to news publication The Daily Caller after severing his links with IS. The pair had used messaging apps to communicate, such as Skype, Kik and WhatsApp.Ahead of his sentencing, on August 28, Amin's lawyer told the US court the youth had helped anti-terrorism investigations in other countries by providing information and evidence.Just how deep the probe extended into South Africa - and what became of Buchs - is unclear from the documents produced in the US court.South Africa's State Security Agency, asked this week about the case, offered no specifics.Spokesman Brian Dube said the agency was "aware of matters that involve, in one way or another, South Africans thought to be involved in global security challenges."As part of our work, we share information with the intelligence community in the continent and the rest of the world."story_article_right2The agency, he added, monitored online platforms, including social media."We continue our work on behind the scenes networks active in online recruiting and possible funding mechanisms" for groups such as IS .In April this year, a 15-year-old South African girl was hauled off a flight leaving Cape Town as she tried to make her way to join Islamic State.South African cyber security expert Haroon Meer said it was becoming increasingly difficult to keep children away from social media."This will be a losing battle. Instead, parents should opt for building strong relationships with their kids, listening to them, and giving them opportunities to share their experiences - aiming to armour them against the negative exposure that will happen."Amin's estranged father, Shukri Abdelrahim, told the US court: "My absence from his life left Ali adrift and looking for a new authority and associates in his surroundings and the internet."..