A special MP/MLA court here on Monday acquitted gangster-turned-politician Mukhtar Ansari and his associates in a case of extending threat to a Lucknow jailor and others about 23 years ago. Special Additional Chief Judicial Magistrate A K Srivastava observed that the prosecution failed to prove the charges against Ansari and his four associates Lalji Yadav, Kallu Pandit, Yusuf Chisti and Alam beyond reasonable doubt.