Kamal Chouhan, an accused in the 2007 Samjhauta Express bombings, on Tuesday confessed in front of the media to the attack that had killed 68 people, including many Pakistani nationals at a place near Panipat in Haryana, two days after his arrest.
However, his family alleged that Chouhan confessed under duress.
Chouhan was remanded to police custody till Feb 23 after he was produced in court on Tuesday.
The National Investigation Agency (NIA), India´s premier terrorism investigation body, on Sunday had arrested Chouhan from Indore.
Chouhand allegedly had planted the bomb in the train. Reports said he is believed to be close to Ramji Kalsangra and Sandeep Dange, two other key accused in the terror attack who are yet to be tracked and for whose clue cash rewards were announced.
Swami Aseemanand and Sadhvi Pragya have been charged in the case along with the absconders. Another accused SunilJoshi is now dead.
The incident had brought to fore the existence of saffron terror in India to counter Islamic terror. NIA is also probing several such incidents, including the Malegaon blast and Ajmer blast.