Scientists from University of Rochester in New York claim to have found feline genetic "pawprint" in the modern-day form of the HIV virus.
They uncovered the genetic sequence in HIV genome that, they say, has descended from an ancient gene carried by lions or tigers over a million years ago.
According to lead researcher Robert Bambara, because the feline version of HIV - FIV - is an old virus, the newly discovered sequence might have been taken up by FIV from host lions or tigers, reports New Scientist magazine.
It is well known that virus started in cats, however, virologist Jaap Goudsmit claimed that ancient cats could have transmitted the virus to monkeys by licking or biting them.
Moreover, members of the cat family have shared their habitat with monkeys both in the East African wild and in Egyptian captivity, where monkeys were kept by the males of the household,while women kept cats.
The team led by Bambara approves that there are chances that HIV virus would have been passed on from ancient felines to monkeys, before being passed onto humans.
Matthew Portnoy of the National Institute of General Medical Sciences told HealthDay that the research could have ramifications for understanding the swine flu virus, which has also picked up genetic information from hosts of different species.