Suspected Islamic State member Mohamed Naser, arrested on charges of motivating people to join the terror group, wrote to his family from Sudan saying he was "comfortable" after joining the outfit and also invited them to join him, the NIA said in a chargesheet filed on Friday.
Naser, 23, who belongs to Thanjavur, is accused of motivating people to join the Islamic State and to wage war in the Middle East as well as India.
According to NIA, Naser's father - the prosecution witness in the case - confirmed that his son, a web developer, had joined the IS.
NIA, which filed a chargesheet in the case on Friday, disclosed that during investigation it was revealed that "Naser had confirmed his father that he joined Islamic State and it was not possible for him to return to the mainstream".
"The facts discussed above corroborated that the accused (Naser) was in Sudan and conveyed to his father that he was comfortable after joining IS and he also extended an invitation to his family to come and join him, " NIA said.
"Investigation has revealed that accused Naser was in contact with his father while he was in Sudan and sent an email from his email ID on October 5, 2015. "
In the letter, he wrote to his father stating that "Take care of Mom and Sumaiya.
I am very safe here.
What you see in the news is just propaganda.
Life here is wonderful . . .
you all are in my duas (prayers) always. "
NIA said Naser went to Dubai in October 2014 and joined an Information Technology company as web developer and global designer.
He disclosed his desire to join the IS to one of his friends in Dubai.
Naser then came across an IS sympathiser on Twitter and on his instruction, he joined a Whatsapp group "Islam Q&A", which is a platform to get news updates and opinions about the IS.
Later, he joined Telegram, a web chat application, of like - minded people in April 2015.
He came in touch with one 'Mad Mullah' who invited him to come to Sudan and join IS.
On September 25, 2015, Naser left for Sudan to join the banned terror group.
Naser was arrested on October 5, 2015 by Sudan Police for concealing his identity and trying to proceed to Syria to join IS.
Naser was deported to India and was arrested on December 11, 2015.
The chargesheet against Naser was filed under section 125 (waging war against any Asiatic Power in alliance with Government of India) of the Indian Penal Code (IPC) and sections 18 (punishment for conspiracy) 18B (Punishment of recruiting of any person or persons for terrorist act), 38 (offence relating to the membership of a terrorist organisation) and 39 (offence relating to the support given to a terrorist organisation) of the Unlawful Activities (Prevention) Act.