Here are 10 developments in the story:
Aseemanand, who has been in jail since 2010, has admitted that he met the reporter, but denied the interview. "On 9th January, 2014, Leena R came to meet me in the jail. I saw her several times as a reporter in the Panchkula court. But on 9th January she came as an advocate and wanted to help me. I refused her proposal...Then she requested me to discuss social work"
He also denied that he had said anything about RSS chief Mohan Bhagwat or Gujarat Chief Minister Narendra Modi. "The story she mentioned in the article is totally false and fabricated. I will take legal action," he writes.
Caravan's editor Vinod Jose said, "I understand the pressure that Aseemanand is under. Our journalist introduced herself as a journalist. Aseemanand was elated that a journalist wanted to tell his story. He himself wanted these interviews."
The RSS has rubbished the interview and raised doubts about it. "The National Investigation Agency has no shred of evidence, even against those in jail. It's just allegations galore. There is something fishy about this whole thing... we're studying the whole thing, we will collect more information about what happened," RSS spokesperson Ram Madhav told NDTV on Thursday.
Caravan says that in a meeting in Gujarat in 2005, Mohan Bhagwat, now the chief of the RSS, heard Aseemanand's plans "to bomb several Muslim targets around India" and said, "It is very important that it be done. But you should not link it to the Sangh."
As a top leader of the RSS' tribal affairs wing, Aseemanand was based for years in the Dangs in Gujarat and focused on making advisasis convert to Hinduism instead of Christianity. According to the Caravan report, he said that in December 1998, after 10 days of communal violence, "Advaniji was the home minister and asked (then chief minister) Keshubhai Patel to rein me in."
Aseemanand allegedly said after that, Narendra Modi met him at an RSS meeting in Ahmedabad and said, "Now it has been decided that I will be the CM. Let me come and then I will do your work. Rest easy."
Caravan says its reporter interviewed Aseemanand in the Ambala Jail in Haryana four times over two years. Jail officials are investigating how the reporter was given access to him.
Aseemanand was arrested in 2010 for his alleged complicity in terror strikes between 2006 and 2008 that included the bombing of the Samjhauta Express in 2007. Nearly 70 were killed on the train which was headed from Delhi to Lahore in Pakistan. The charges against him include murder and sedition.
After he was arrested, he confessed in court in December 2011 to his role in the terror attacks he was charged with. He also implicated the RSS. However, he later retracted his confessions, alleging that he had been coerced to make them by investigating officials.
The BJP has alleged that the interview is concocted and blames the Congress's "dirty tricks department" for trying to damage the BJP and the RSS in election season.