Junaid Hussain--an Islamic State (Isis) terrorist from the UK, known for his role in leaking online the phone numbers and home addresses of American soldiers--was reportedly killed in a US drone strike in the Syrian city of Raqqa on Wednesday.

According to media activist group Raqqa is Being Slaughter Silently, Junaid Hussain--who went by the nom de guerre Abu Hussain al-Britani--was killed on 24 August outside his house in Raqqa, de facto capital of the Caliphate in Syria.

The 21-year-old Isis cyber cell chief was on the "kill list" of the US forces and his movements inside Raqqa were being monitored. He was said to be the second most valued target after Jihadi John and was number 3 on the CIA "kill list".

A US official told CNN, "We have a high level of confidence he was killed."

Hussain was also linked with the shooting at the 'Draw the Mohammed' Cartoon in Garland Texas in May. Investigations have found that Hussain, who was using his nom de guerre Abu Hussain al-Britani, knew about the attack and even took credit for the failed attack.

Hussain was married to a 44-year-old British rocker Sally Jones. Dubbed as "Mrs Terror" in the UK, Jones converted to Islam and now goes by the name Sakinah Hussain. She had also fled to Syria with her husband and son.

At the age of 18, Hussain was convicted for illegally gaining access into the address book of former British prime minister Tony Blair. He served six months in prison and after coming out on bail, fled to Syria, according to the Daily Mail.