"Attempts at character assassination are one of the most despicable of human behavioural patterns. I am more than certain that the judiciary would vindicate me and put to rest once and for all such unholy attempts," he said in a statement.
The two others facing the probe apart from SM Krishna are former Chief Ministers of Karnataka - N Dharam Singh and HD Kumaraswamy.
The FIR was lodged by the Lokayukta police on the direction of NK Sudhindra Rao, Lokayukta Special court judge after a private complaint was filed by TJ Abraham.
"There has been no de-reservation of forests (during his tenure) as is being incorrectly reported," said Krishna who served as the Chief Minister of Karnataka from 1999-2004.
"The (state) cabinet sometime in 2003 decided to de-reserve mineral wealth for mining. Government is fully empowered to take such a decision as per the Minerals Concession Rules, 1960," he said.
He further said that the cabinet notification was issued after the cabinet decision that "clearly states that applicants for mining leases have to obtain 'no objection certificates' from the forest department."
When a gazette notification has been issued it is abundantly clear that nothing which has been done in secret," he said.
"I wish to point out that I never retained the portfolio of Mines and Geology. Further to the best of my knowledge no mining licence was issued during my tenure," he said.
"In view of the above, there is no wrongful loss to the government. Consequently, there can be no wrongful gain," Krishna said.
Talking about the then Lokayuta Santosh Hegde, Krishna said that he "conducted a very detailed and comprehensive enquiry into the issue of mining from 1999 to 2010 which covered my tenure as Chief Minister from 1999 to 2004. There is no indictment of me anywhere in the Lokayukta report. The fact that Justice Santosh Hegde has gone on record in public only further confirms this."
He further said that he will take "appropriate action at the appropriate time, I consider it necessary to clarify matters. This is necessary as silence on my part would give rise to speculation."