He also stated that the demands of the Maoists were "justified" and government should address the issues facing them.
Hours after the Maoists named him as one of three mediators for negotiations with the government, Bhushan said that he would not mediate on the issue.
"No, I am appealing to the Maoists to unconditionally release the collector. I agree to most of their demands which are justifiable but the collector should not be used as a bargaining chip," he told PTI when asked if he would act as a mediator.
"Menon is an innocent officer. If the government is serious about addressing the root causes of Naxals, I am quite happy to be part of any negotiations then," he said.
The lawyer said the demands for ending operation 'green hunt' and release of innocent tribals are "justified".
Government should also address issues facing them like handing over large tracts of land to big corporations, he said.
After the Chhattisgarh government offered to hold talks to secure the release of the Sukma district collector, Maoists last night named three mediators, including former National SC/ST Commission chairperson B D Sharma and president of All India Adivasi Mahasabha Manish Kunjam.
Kunjam has also declined the Maoists offer citing regional circumstances and party obligations.
In a statement, the Maoists also termed Menon's health as critical and asked the mediators to bring medicines along with them.
The Maoists asked the government not to indulge in "delay tactics" as Menon's health was deteriorating.