A National Investigation Agency (NIA) Special Court at Nampally in Hyderabad on Monday, citing lack of evidence, acquitted five accused, including Naba Kumar Sarkar alias Swami Aseemanand, in the case of the bomb attack on the Mecca Masjid 11 years ago, reports said.
The blast, using an improvised explosive device, killed nine persons inside the masjid near the historic Charminar of Old City.
The others acquitted are Devendra Gupta, Lokesh Sharma, Bharath Mohan Lal Rateshwar and Rajendra Choundary.
The NIA had originally charged 10 persons with plotting and carrying out the attack on May 18, 2007.
Accused Sunil Joshi of Madhya Pradesh, a former Rashtriya Swayamsevak Sangh (RSS) pracharak, was murdered when the case was investigated.
Two other accused, former RSS pracharak Sandeep V. Dange and RSS activist and electrician Ramchandra Kalsangra, also from Madhya Pradesh, have been eluding the investigators.
Investigations against two others from the same State, Tejram Parmar and Amith Chowhan, are continuing.