The CBI suspects that RSS's Mhow-based pracharak (preacher) Sunil Joshi's murder could be linked to individuals who were part of his Hindu terror network.
Joshi, suspected executor of May 2007 Mecca blast and October 2007 Ajmer dargah blast, was shot dead on December 29, 2007.
"Joshi was killed at a time a few investigating teams were closing in on him and his associates, based on the fact that the explosive device used in Mecca and Ajmer blast were similar to the one Joshi had attempted to utilise four years ago to target a Muslim congregation in Bhopal," said a CBI officer.
"It was at that moment when Joshi was silenced."
HT had first reported that Joshi and his close associate, the absconding Ramchandra Kalsangra, who along with the former was the planter of the bombs used in Mecca and Ajmer blasts, made their "first dry run" of their bomb type on December 23, 2003 in Bhopal to target those attending a Muslim congregation.
The duo's typical bomb comprised RDX and TNT, packed in 10 inch-by-3 inch cylindrical metal pipes, connected with wires to a mobile phone set, whose alarm functioned as the trigger device.
The CBI also suspects that Joshi's alleged "intimacy" with September 2008 Malegaon blast accused Pragya Singh Thakur had become a sore point between the former and others in his terror network.
Thakur's LML Freedom bike, which she had given to Joshi, was used by Kalsangra in the Malegaon blast.
The Madhya Pradesh police had initially suspected that Joshi's murder was fallout of his then status as a suspect in the murder of a local Congress politician and his son.
Though the police later also probed the involvement of the proscribed Students' Islamic Movement of India (SIMI) in his murder, they failed to make a breakthrough.