In a letter to Singh last month, Roy, who recently quit the Trinamool Congress to join the BJP, alleged that his phones were been "illegally tapped" by the West Bengal government.
"I have received your letter dated October 3, 2017, regarding alleged monitoring of your movements by the state administration. The matter is being examined for appropriate action," Singh has written to Roy.
Roy received Singh's reply today.
Roy has also filed a case against the state administration in the Delhi High Court on the matter.
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