Replying to an RTI query, the Ministry of External Affairs (MEA) said it had sent a formal request to the US for the extradition of Anderson in April 2011.
"However, the details of the request and copies of the documents contained therein deal with security of the state and its relation with foreign state. The information is exempted under Section 8 (1) (a) of the RTI Act, 2005," it said.
The section bars disclosure of information which would prejudicially affect the sovereignty and integrity of India, the security, strategic, scientific or economic interests of the state, relation with foreign state or lead to incitement of an offence.
Further, disclosure of the details of the case may also impede the process of investigation or apprehension or prosecution of offenders in the case under discussion, it said, adding, "Hence, such information is exempt under (RTI) Act."
Anderson is the prime accused in the Bhopal gas tragedy case. Over 5,200 people had died in the world's worst industrial disaster at the Union Carbide plant in Madhya Pradesh on the intervening night of December 2-3, 1984.
A Group of Ministers is deliberating on ways to safely dispose of 346 MT of toxic waste from the site.
As per official data, compensation of over Rs 3,000 crore has been given in 5,295 cases of death, 4,902 for sustaining permanent disability, 5,27,894 cases of minor injury and 35,455 cases related to temporary disability among others.
India has received six requests of extradition from various countries last year, as against 17 each in 2011 and 2010. Whereas, 10 requests for extradition of various individuals was sent to foreign countries last year, 11 in 2011 and 17 in 2010, the RTI reply said.