Three people died in a blast at the Ajmer Dargah during an Iftaar party in 2007.
In a major blow to the National Investigating Agency's Ajmer blast trial, 13 crucial prosecution witnesses have now turned hostile and gone back on their testimonies.
In October 2007, a bomb blast in the holy Ajmer Dargah killed three and wounded more than a dozen. The Rajasthan Anti-Terror Squad (ATS) and later the NIA chargesheeted 12 people who were present and former members of the RSS, or belonging to fringe groups.
This same group of zealots are accused of a wave of what came to be known as "Saffron Terror" bombings through 2007, setting off deadly explosions in Muslim-dominated areas like the Ajmer Dargah, the town of Malegaon and the Mecca Masjid in Hyderabad.
"The whole case of the prosecution depended upon these star witnesses," said Ashwini Sharma, the assistant public prosecutor of the Ajmer blast case. "And all those who gave the statement, under Section 164 (of the Code of Criminal Procedure), in front of the magistrate, all turned hostile in court."
Significantly, their statements - now retracted - were recorded in before a judicial magistrate to ensure there is no pressure from investigators. But starting in November 2014, they began to turn hostile claiming that they were pressured by the NIA to testify. The last such flip by a witness was in May 2015.
But Mr Sharma told NDTV that he "had asked every single witness if they had ever complained to the court that the ATS had pressurised them. They said that they had never got an opportunity to complain to anyone."
Significantly, one of the witnesses who has done a u-turn is Randhir Singh, now a minister in the BJP's Jharkhand government. According to Mr Sharma, Mr Singh claimed in his testimony to the ATS to have seen Mr Gupta and another RSS pracharak named Manoj test fire a weapon.
But according to Mr Sharma, Randhir Singh turned hostile in May this year. Just four months ago, Mr Singh defected to the BJP from the Jharkhand Vikas Morcha (Prajatantrik) and was made a minister.
"Originally Singh had said that the accused test-fired a revolver, but in court he denied making such a statement," said Mr Kumar.
Mr Singh however told NDTV that he has not made any such retraction.
NIA sources told NDTV that there was no pressure on any witnesses. "Our job is to investigate. We cannot control the stand taken by witnesses," said a senior NIA official.
All 13 witnesses were either RSS workers or functionaries, according to Mr Kumar, who examined them in court.
The BJP refused to comment but RSS ideologue Rakesh Mishra told NDTV that the change in witness stands only showed that the case was politically motivated. "All these cases are a political conspiracy against the RSS," said Mishra. "It is the right of the witnesses to withdraw if they were under pressure."
"The fact remains that once BJP government comes in, these cases (involving RSS members) will be diluted and put on hold," said Digvijaya Singh, senior leader of the Congress party. "This is part of larger conspiracy at a higher level."
The Ajmer probe has been mired in controversy ever since the chargesheet named Indresh Kumar, National Executive Council member of the RSS, as a part of the conspiracy.
According to the NIA's chargesheet, he attended a secret meeting in Jaipur's Gujarati Samaj guest house just before the Ajmer blasts, where all the accused were staying. In the meeting, Indresh Kumar is said to have told the plotters to associate themselves with religious associations to avoid suspicion. But he was never included as an accused, for reasons that remain unclear.
This latest revelation, of witnesses turning hostile, is likely to add to the controversy surrounding cases of "Saffron Terror". Earlier this week, Rohini Salian, special public prosecutor in the Malegaon case where again Sangh Parivar members are accused had said since the government changed she has been asked to go soft on the case by an NIA official.