Mukherjee's comment on the letter questioning role of central forces in Jangalmahal came a day after chief secretary Samar Ghosh said that the secretariat had not received the letter.
"I have not seen any such letter as yet," Ghosh told reporters on Saturday. Chief Minister Buddhadeb Bhattacharjee had also expressed ignorance of the letter even after its contents were disclosed by the union home ministry on December 24.
Chidambaram's strongly worded letter to Bhattacharjee comes in the wake of ally Trinamool Congress chief Mamata Banerjee alleging misuse of central security forces in the state and offering to quit if her charge was proved wrong.
"If these armed cadres continue to take upon themselves the duties of maintaining law and order, I wonder what the role of security forces is, specially central para military forces which have been deployed at the request of the state government?" Chidambaram had said in the letter.
His letter came a day after a Trinamool Congress delegation had met Prime Minister Manmohan Singh and conveyed to him alleged misuse of central security forces in West Bengal.