The letter threatened that Team Anna would be attacked by deadly needles if they kept demanding for a Lokpal Bill.
The issue is being taken seriously by the Delhi Police, who have now filed an FIR and is on a manhunt for the sender of the letter.
The letter reads that "a needle team, which has prepared 500 HIV positive needles, would inject the virus in atleast 1,000 people at the demonstration". The anonymous letter was sent on Dec 9 to the DCP Central office.
An FIR under Sections-505 (2) (statements conducting to public mischief), 506 (criminal intimidation) and 507 (criminal intimidation by anonymous communication) of the IPC have been filed in the case.
The police are dubious that "this letter seems to have been posted to the DCP's office from Delhi itself."
"We are trying to ascertain the identity of the sender though, after lot of discussions, we have also come to the conclusion that it might be a prank letter sent by some criminals. But since it is related to Anna Hazare, we don't want to take any chances as there is already a threat to his life and to the large number of people who congregate at his demonstrations," said a police officer.
The letter said that around 50 "volunteers in this needle group who are trained and they would use the needles cleverly on atleast 1,000 people".