A suspicious packet sent to the home of Urmila Matondkar was being tested for anthrax.
"We received a packet with suspicious material from Urmila`s residence on Saturday," the duty officer at the Haffkine Institute, said.
The leading biomedical research and training institute tested over 50 envelopes containing powdery substances from the western states of Maharashtra and Goa last month but none tested positive for anthrax.
A lab in Thane, outside Mumbai, found undisputed evidence of anthrax in a letter to Maharashtra deputy chief minister Chhagan Bhujbal. But the Haffkine Institute tested the substance and found no anthrax. The powder has been sent for a third test.
US President George W. Bush on Saturday called the recent anthrax cases "a second wave of terrorist attacks". The number of confirmed anthrax cases in the United States is 17.
