LONDON — For agents of the Islamic State, the front lines have long been drawn: There is combat in the Middle East and there is the battlefield of Twitter.

One of the most influential operators have been the person behind the widely-followed Twitter account @ShamiWitness. Before the account was shut down earlier today, following revelations by Channel 4 News, @ShamiWitness had 18,000 followers.

As Channel 4 News reporting revealed, the man operating the account is an executive in Bangalore called Mehdi who works for an Indian food conglomerate. (Channel 4 News has chosen not to reveal his full name as he says his life would be in danger if his true identity was made public.)

On Thursday afternoon, after Channel 4 News broke the news about Mehdi, the @ShamiWitness account was closed down, spurring Twitter commentary.

Syria watcher tweeps are having a bit of a uncomplimentary Twitter wake for @ShamiWitness at the moment — Eliot Higgins (@EliotHiggins) December 11, 2014

One of the main ISIS fanboys, ShamiWitness, was just revealed by Channel4 News to be an executive in Bangalore — Molly Crabapple (@mollycrabapple) December 11, 2014

In a phone interview, Mehdi said he would have gone to join Islamic State himself, but that he was constrained by his family who are financially dependent on him: "If I had a chance to leave everything and join them I might have," he said. But "my family needs me here."

@ShamiWitness has been one of the strongest voices to directly and indirectly support the radical group, said Laith Alkhouri, a researcher with Flashpoint Partners.

"We cannot ascertain how involved he is with the group, but he is likely privy to a great amount of information within the confines of Iraq and Syria," Alkhoury said. "I consider him a good jihadi source."

Posting several thousand times every month, @ShamiWitness spread ISIS propaganda with tweets such as this one: "Islamic State brought peace, autonomy, zero corruption, low crime-rate."

Using the @ShamiWitness account, Mehdi tweeted the video of the execution of US aid worker Peter Kassig five times. While on his private Facebook page, Mehdi regularly posted pictures of pizza dinners with friends, and Hawaiian parties at work.

One of his Twitter followers was a 23-year-old British man named Iftikhar Jaman from Portsmouth who went to Syria to fight for ISIS. Jaman was killed while fighting in Syria in December last year. Afterward Mehdi tweeted about Jaman that: "you bros talked the talk, walked the walk."

The Washington Post has reported that ISIS draws 1,000 new foreign fighters into its rank every month from more than 80 countries.

According to some jihadi experts, two-thirds of foreign fighters for ISIS who are active on Twitter followed @ShamiWitness.

When I asked him if he condoned the brutality of ISIS, such as beheadings, he replied: "Not all methods, no. But [most]. Beheadings are discussed in Quran and Hadith itself. I don't think any honest muslim will ever tell you he's against beheadings per se."

He also admitted he had been in regular contact with several foreign fighters including a handful of British jihadis but he denied playing any part in their radicalization.

"Just because somebody follows me [on Twitter] that doesn't mean I am the reason for their moving to ISIS," he said. "There are real reasons why people get radicalized."

Simon Israel is the home affairs correspondent for Channel 4 News where he covers crime, police, terrorism, legal, race, immigration, social justice and prisons.