Ranchi, Jan. 1: Mahendra Singh Dhoni left for Mumbai this afternoon after spending New Year’s eve at home with friends and family even as the police offered no fresh clue on the origins of the extortion threats his father received in the last two days.

No FIR has been lodged in the case so far, but the police have been extra-cautious in tightening the Z-category security ring around the skipper and his residence.

Senior superintendent of police (SSP) Sampat Meena reiterated an FIR would be lodged only after completing primary inquiries in the case. “Meanwhile, we are verifying all that has been written in the letter and efforts are on to identify the handwriting.”

Dhoni’s father Pan Singh received two letters — one on Monday and another yesterday — claiming to be from a member of Dawood Ibrahim’s gang demanding Rs 50 lakh. Based on the letter, police officials have so far visited Mani Tola and contacted the brother of Mohammed Tasleem, who has claimed to have written the letter identifying himself as “Chhota Dawood, the man wanted in Orissa, Bengal, Bihar and Jharkhand.”

But additional police superintendent of Hatia, A.Vijayalaxmi, who is in-charge of the case, refused to comment.