The BJP has dared the government to clarify whether Lashkar-e-Taiba operative David Coleman Headley told Indian investigators that 19-year-old Ishrat Jahan shot dead by the Gujarat police in 2004, was a terrorist.
The party is also demanding an explanation for why paragraphs that detailed this alleged revelation were deleted from a report on the questioning of the Pakistani American in a US jail three years ago.
The changes to the interrogation report, which were made by the National Investigating Agency on the grounds that they were "hearsay", were reported exclusively by NDTV on Thursday.
"Why were these paragraphs deleted? The Congress cannot decide who is terrorist and who is not...it's for the courts to decide, " said the BJP's Nirmala Sitharaman.
Why and how Ishrat, who was from Mumbai, was gunned down by the Gujarat police is suffused with political colour and creates a new boldface controversy for chief minister and senior BJP leader Narendra Modi. His party says that the government is concealing Ishrat's terror links to discredit Mr Modi, who is the front-runner for the BJP's prime ministerial nomination.
"The government is using the CBI to hit at Narendra Modi and then Home Minister Amit Shah," said BJP spokesperson Nirmala Sitharaman.
In February this year, the Intelligence Bureau wrote to the CBI to say that Mr Headley had told the FBI that Ishrat was part of a terror module which was planning attacks at temples in Gujarat. (Watch: Agency war over Ishrat Jahan chargesheet)
Whether Ishrat was a terrorist working with the three men killed with her has not been addressed by the CBI, which filed its first chargesheet in the case this week in a court in Ahmedabad. It described the shooting as a joint operation between the police and intelligence bureau in Gujarat, but did not comment on whether Mr Modi had been informed in advance about the plans for the encounter.