The Bangalore police arrested the 24-year-old MNC employee who worked as a manufacturing executive during the day and for the terror outfit ISIS during the night, the Karnataka DGP L Pachau said while addressing a press conference.
A mobile phone and a laptop has been seized from his at the time of his arrest.
The son of a retired West Bengal state electricity board, Mehdi was residing in Bangaluru in a rented apartment since 2012.
His parents and two elder sisters live in West Bengal.
The suspect developed keen interest in the affairs of ISIS and had been operating the Twitter account from the past several years.
Mehdi was arrested by police and is being quizzed by the intelligence agencies about his involvement with the Islamist terror outfit.
Mehdi, the man behind the Twitter handle, is an executive in Bengaluru working for an Indian conglomerate, according to Britain's Channel 4 News.
"His tweets, written under the name Shami Witness, were seen two million times each month, making him perhaps the most influential Islamic State Twitter account, with over 17,700 followers," the channel reported.
It has been said that Mehdi's Twitter handle helped in propagating the ISIS agenda and his tweets were reposted and have reached across to millions of people.
The Twitter handle was being followed by foreign jihadis.The account @ShamiWitness has been closed by the closed by Twitter now.
Kalyan youth Areeb Majeed, who left his home earlier this year to join ISIS, was following the Twitter handle. He has confessed to being influenced by Mehdi's Twitter account.
Majeed was arrested shortly after his return to Mumbai.
