A group of tiger biologists from India, USA, UK and Russia have debunked a report which claimed that the world's wild tiger population is on the rise.

"We do not find this report and its implications scientifically convincing," said a statement issued by four tiger biologists - Dr K Ullas Karanth from Wildlife Conservation Society India, Dale Miquelle, director of Russia Program of Wildlife Conservation Society, John Goodrich of Panthera US-based Panthera Corporation and Arjun Gopalaswamy from the University of Oxford.

Using flawed survey methodologies can lead to incorrect conclusions, an illusion of success, and slackening of conservation efforts, when in reality grave concern is called for, they said.

Citing a recent World Conservation Union (IUCN) assessment which showed 40 per cent habitat loss in the last decade and a spike in poaching pressure in many regions, they said Cambodia, Vietnam, Lao PDR and China have virtually lost viable tiger populations in recent years.

A recent report by WWF and the Global Tiger Forum (GTF) had said that the number of wild tigers has been revised to 3,890 compiled from IUCN data and the latest national tiger surveys.

In the 2010 Tiger Summit in Russia, governments had agreed to achieve a goal to double wild tiger numbers by 2022