Siful Haque Sujan was wiped out by a US drone strike near Raqqa in Syria on December 10.
The 31-year-old computer expert, who had spent more than a decade working in the UK, became a leafing figure in the savage death cult’s hacking campaign and their operation to beat Western surveillance.
The fanatic became a senior figure for ISIS – also known as Daesh – after replacing another hacker from the UK, Junaid Hussain, who was blasted by an air strike in August.
According to the Pentagon, the Bangladeshi businessman – who lived near Cardiff before joining ISIS – was killed as part of a campaign to obliterate the brutal militants by "striking at the head of the snake".
Sujan's death came less than 18 months after he left his home, where he had studied and worked as a director of a computer firm.
Former business associates said he had never shown signs of extremism while living in Britain.
One business associate, who had known Sujan for more than 10 years, said: "He was an entrepreneur and he became a friend.
"He helped everyone create websites for their businesses. He was always coming up with ideas.
"He was very intelligent and persistent but was just a normal run of the mill chap.
The expert entered Britain in 2003 and went on to study computer system engineering at the University of Glamorgan before establishing a Newport-based computer firm with his brother.
An immigration tribunal in 2014, where he unsuccessfully applied for a special visa to remain in the country because of his sought-after skills, heard he was "an individual of considerable ability".
Sujan left the UK 2014 after telling friends he and his wife wanted to return to Bangladesh.
Neighbour Donna Davies, 33, who lived near Sujan in Pontypridd. said he usually wore a suit and drove high performance cars.
She said: "The only time I would see him was late at night. His wife and son rarely left the house, you never saw them.
A spokesman for Sujan's former university said: "In common with the UK's other major international universities, we take seriously the shared effort to counter radicalisation,Express reported.
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