"Accepting recommendations of the police, the district magistrate and collector of the west Tripura district has imposed NSA against the dreaded extremist leader for many crimes and massacre," west Tripura district police chief R G K Rao said Friday.
Debbarma, chief of outlawed outfit All Tripura Tiger Force (ATTF), was facing Interpol's red corner notice for a number of massacres and other crimes.
Senior police and intelligence officials have interrogated him and obtained a large amount of information, which the police refused to disclose to the media.
"I was pushed back by the Bangladesh security forces Jan 16 through the Dawki India-Bangladesh border in Meghalaya. Tripura Police brought me here Jan 18," Debbarma told reporters while he was being escorted to the court by a heavy contingent of police forces Thursday.
However, a senior police official told IANS: "Separatist outfit ATTF's self-styled president was arrested Jan 23. Then senior police and intelligence officials have interrogated him several times before he was produced in the court."
The militant leader admitted that he was arrested by the Bangladesh security forces in Dhaka in December last year.
Tripura's opposition (Congress) leader Ratan Lal Nath demanded that he be interrogated by the National Investigative Agency (NIA).
Debbarma, 41, had formed the ATTF in 1993. He was also the founder of the outfit's 'political wing' Tripura People's Democratic Front (TPDF), also an outlawed group. He had carried out a number of killings.
The union home ministry banned the ATTF and another separatist outfit National Liberation Front of Tripura (NLFT) April 3, 1997.
The Tripura Police had earlier declared a reward of Rs.2 lakh to anyone who could give information about his whereabouts.
According to the police, following the advice of the union home ministry, Tripura and the CBI, Interpol had issued a red corner notice against the dreaded militant.
The ATTF and NLFT had hideouts and training camps in Bangladesh, and have been demanding secession of Tripura from India.
Top intelligence sources here said Debbarma, along with his three women associates, was picked up by sleuths of Bangladesh agencies in December last year and kept in Dhaka.
Debbarma is the most dreaded and militant leader pushed back by Bangladesh after ULFA's (United Liberation Front of Assam) founding member and chairman Arabinda Rajkhowa, who was pushed back in December 2009.
Tripura shares an 856-km border with Bangladesh, some of it unfenced and running through dense forests and mountainous, making it porous and vulnerable and advantageous for the terrorist outfits for their cross-border movements.