Sadhvi Pragya and Lt Col Purohit were charged with plotting the 2008 Malegaon blasts.
The AAP today questioned the "credibility" of the National Investigation Agency (NIA) after charges against Sadhvi Pragya Thakur were dropped in the 2008 Malegaon blast case and accused the BJP of weakening the country's premier counter terrorism body.
The party also attacked NIA and BJP for questioning the role of Maharashtra ATS chief Hemant Karkare who was killed, who was heading the probe when Sadhvi Pragya and Col Shrikant Purohit were arrested and asked it to apologise for raising doubts over his investigation.
"The BJP and the NIA should say sorry for raising doubts about Hemant Karkare who laid his life for the nation. He had served in the RAW for a long time and only officers with integrity are chosen in the spy agency," AAP leader Ashish Khetan said.
Mr Karkare was killed during 26/11 Mumbai terror attack in 2008 and was honoured with the Ashoka Chakra on January 26, 2009.
Raising doubts over NIA Director General Sharad Kumar's role in the probe pertaining to right-wing groups, Mr Khetan demanded investigation into how Rs 4 crore of secret fund was used as over 49 witnesses have turned hostile in the case.
"The BJP is weakening the credibility of investigating agency. Earlier the CBI was being called a caged parrot. Now the NIA is also like a caged parrot," Mr Khetan alleged.
The AAP leader also alleged that the NIA was systematically weakening cases against right wing groups.
Targeting Mr Kumar, Mr Khetan said the NIA chief has been retained on "contract" despite his retirement, which is contrary to the IPS rules and service norms.
"In the Samjhauta blast case which is going on in Panchkula, Kumar watered down NIA's response to Swami Aseemanand's bail plea. In different terror cases in which RSS people are involved, 49 witness have turned hostile. These witnesses have been pressurised to change their statements," he alleged.
"There should be an investigation on where Rs 4 crore of secret fund was spent," Mr Khetan further alleged. He accused both BJP and the Congress-led UPA, which was in power till 2014, of "politicising" the terror cases.