5. Hawala scandal (1991): Hawala was a US $18 million scandal that implicated some of the country's leading politicians including the then Prime Minister P V Narasimha Rao, L K Advani, V C Shukla, P Shiv Shankar, Sharad Yadav, Balram Jakhar and Madan Lal Khurana.
The arrest of the Jain brothers, the hawala brokers, led to the seizure of now famous `Jain diaries' that had details of all the payments.
However, the CBI's entire case against the prominent personalities cutting across party lines named in these diaries collapsed in court. Special CBI Judge V.B. Gupta held that none of the statements and confessions of the accused was admissible in court since they were given to the CBI.
Ruling on the PIL filed by Vineet Narain, the Supreme Court of India directed that the Central Vigilance Commission should be given a supervisory role over the CBI.