Contamination of a portion of Chilika lake around Nalabana Birds Sanctuary in Orissa has resulted in the deaths of over 1,700 migratory birds within a span of 45 days, a senior official said, and ruled out bird flu as the cause of birds' death.

"During the months of December and January 2005, a portion of Nalabana Birds Sanctuary got infected due to congregation of a large number of birds. Contamination caused by huge amount of droppings and sudden rise in temperature contributed to the deaths of over 1,700 birds," Chief Wildlife Warden Suresh Mohanty told PTI.

Mohanty, however, made it clear that the deaths had nothing to do with bird flu.

He said the deaths were due to pastaeurellosis, a disease of the bacterial infection or fowl diarrhoea.

A large number of pintails, gadwalls, shoveller and seagulls died in the 15.59 sq km sanctuary area, where a large number of avian guests congregated during the winter season.

"Following the deaths, we have tested the samples of these birds in three laboratories including the high secuity animal disease laboratory of Bhopal and the veterinary college of Orissa University of Agriculure," Divisional Forest Officer of Chilika Wildlife Division Abhimanyu Behera said.