The court has directed ADGP Lokayukta to submit the report on the probe on Jan 6, 2012.
The two other apart from Krishna's successor are N Dharam Singh, Congress leader and HD Kumaraswamy, Janata Dal-Secular.
The order came after a complaint was filed by T J Abraham, Bangalore business who alleged that Krishna, Dharam Singh and Kumaraswamy allowed illgeal mining when they were the chief ministers.
Apart from the chief ministers, Abraham also accused 11 serving and retired senior officials for their involvement in the scam.
Krishna's name often came out after illegal mining scandal broke out in the state in 2006, but he refuted all allegations charges against him.
Meanwhile, the Bihar Lokayukta Bill, 2011 has been approved by the State Governor that will bring the Chief Minister and ministers under its ambit.
Devanand Konwar, Governor gave his approval for the bill on Friday, Dec 2, said Raj Bhawan sources.
The step to implement a Lokayukta was, however, questioned by opposition parties on why the bill was rushed adding that a debate should have taken place before its enactment as legislation.
The approval was also heavily criticised by Team Anna members-Arvind kejriwal and Shanti Bhushan who called it a weak and a replica of the Centre"s Lokpal bill.