AURANGABAD: The Madhya Pradesh Anti- Terrorism Squad (ATS) has detained a doctor from Nanded district of Maharashtra for allegedly sending suspicious envelopes to controversial BJP MP Pragya Singh Thakur, police said on Saturday.

Thakur had lodged a complaint with the Madhya Pradesh police on Monday alleging that she had received some envelopes containing poisonous chemicals in them. Police had seized 3 to 4 envelopes from the BJP MP's residence, some of which had letters written in Urdu.

Talking to PTI, inspector Pradeep Kakade of Itwara police station in Nanded said that during its probe, the MP ATS found that Dr Sayyed Abdul Rehman Khan (35), who runs a clinic in Dhanegaon (in Nanded district), had sent these suspicious envelopes to Thakur.

"The MP ATS detained Khan on Thursday evening from Dhanegaon. He had been on the police's radar for the last three months, as he had previously written letters to some government officials, claiming that his mother and brother had terror links and they should be arrested," Kakade said.

The officer said that Khan was previously arrested for writing these letters.

"The police tried keeping a tab on him using his mobile phone location. However, he would leave his phone at home and travel to Aurangabad, Nagpur and other cities to post these letters," Kakade added.

Khan also had a dispute with his brother and was earlier arrested for assaulting him, the official added.

Based on Pragya Singh Thakur's complaint, Kamla Nagar police in Bhopal had registered a case against an unidentified person on charges of criminal intimidation and voluntarily causing grievous hurt.