Lucknow, Jan 4 (IANS): The police chief of Pratapgarh district in Uttar Pradesh Saturday received a death threat and an extortion demand of Rs.5 lakh, police said.

The threat was contained in a letter addressed to the superintendent of police of Pratapgarh, asking him not to investigate the murder, late December last year, of local lawyer Raj Dutt.

The police confirmed that the letter was received through post.

Superintendent of Police (SP) Surendra Kumar Verma had only recently taken charge.

The person who authored the threat said that if a probe was conducted into the murder of the lawyer, who had served also as president of the Junior Bar Association, the superintendent of police would meet the same fate as Zia-ul-Haq, the circle official of Kunda, also in Pratapgarh district, who was killed last year.

The letter said that if the police officer was friendly, he stood to earn tens of millions of rupees.

It also put forth a demand of Rs.5 lakh as protection money, and named a location where the money could be delivered.

The superintendent of police dismissed the letter as the handiwork of a mentally unstable person. A First Information Report has been lodged against "unknown persons".