Bhopal, Aug 20 - The depleting number of big cats in Madhya Pradesh has gone down further with one more tigress found dead at Bandhavgarh national park and her three cubs also untraceable, wildlife officials said Thursday. This is the third tiger death at Bandhavgarh this year.

'Park employees saw the body of the tigress aged around 6 years in Pator range of the park Tuesday evening. No injury marks were found on her body and she is suspected to have died of consuming some poisonous thing,' said Chief Wildlife Warden R.S. Negi.

He said the tigress had three cubs - one male and two female, aged around 7 months, but there was no trace of these cubs too after the tigress's body was found.

Negi said a deputy ranger saw the tigress in distress on Tuesday and reported the matter. The tigress went under a culvert, where it was later found dead.