The Apollo Hospital in Hyderabad said it was not aware of any threat being issued to one of its doctors, who treated tennis star Sania Mirza [Images].

There were reports that Dr K J Reddy, a senior orthopedic surgeon at the hospital, had received four letters -- two from Pakistan, one from Bangalore and another from Uttar Pradesh -- warning him against extending treatment to Sania as she has brought "bad name to the religion".

"Dr Reddy is on a week's leave and is away in Goa [Images]. He has not informed us or the police about the alleged threat letters. We have not been able to contact him so far," hospital sources said.

Sources denied the reports that one of the letters was also addressed to the hospital CEO Dr Hari Prasad.

"The statement (regarding the letters) has not emanated from us. We are not responsible for it. It is for the doctor to clarify," they said.

The media report said the surgeon had received the first letter in March this year, soon after he had treated the tennis star for her injuries. The letters warned the doctor that he would face serious consequences if he continued to provide treatment to Sania, the report said.