On 22 July 2008 three BJP MPs showed cash in the Lok Sabha during a trust vote. Six of seven accused were discharged in 2013.
India and the US agreed to work towards full civil nuclear cooperation.
The Left withdrew support over the nuclear deal, forcing a confidence vote.
Three BJP MPs emptied bags of notes in the House, alleging a bribe to abstain.
The UPA survived by 19 votes and could go ahead with the nuclear deal.
The margin, the majority mark and the abstentions.
A committee chaired by V. Kishore Chandra Deo was set up to examine the claims.
Who sat on the committee.
It cleared Amar Singh and Ahmed Patel, and asked an agency to follow the money.
A police case was opened. For two and a half years, no one was arrested.
A cable quoted an aide speaking of a Rs 50 crore fund to buy MPs.
Rs 1 crore, Rs 9 crore, Rs 50 crore: not one money trail.
The court criticised the police for doing little in two years.
From the House to the first arrest.
Police alleged Rs 1 crore paid as an advance on a Rs 9 crore deal.
Amar Singh and two former BJP MPs were arrested. Kulkarni followed on 27 Sep.
Granting bail, the court said the accused appeared to have joined a sting.
Amar Singh, Kulkarni and the three MPs were discharged. Only Saxena faced proceedings.
What happened to each accused.
Only two of five sources are court orders.
No court has said who supplied the cash shown in Parliament in 2008.
Read the complete story, FAQs and key facts.