The researchers, including study author Jean-Christophe Plantier of the University of Rouen, studied a 62-year old HIV-infected Cameroonian woman who moved to Paris in 2004 and began to have symptoms shortly afterwards.
Further tests following discrepancies in her viral load showed she was infected with a new strain of HIV that more closely resembled SIV from gorillas than HIV from humans.
The woman had no reported contact with gorillas, and had lived in a semi-urban environment in central west Africa before moving to Paris, however.
HIV currently has three established lineages, M, N and O, all of which came from chimpanzees.
The research team, which also included David Robertson and Jonathan Dickerson from the Faculty of Life Sciences at The University of Manchester, published their findings in the journal Nature Medicine.
The new HIV variant appeared to be the prototype of a new lineage derived from gorillas, they said.
What's more, there was no evidence of recombination with the other known lineages.
Based on their tests, the researchers suggested a new lineage, called HIV-1 group P.
Most of the 33 million people worldwide living with HIV have been infected with the HIV-1 virus group M.
People carrying viruses in groups N and O are mainly confined to Cameroon.
HIV is thought to have developed in humans who ate bush meat (which includes the meat of monkeys and chimpanzees) infected with the Simian Immunodeficiency Virus (SIV) found in chimpanzees.
HIV is believed to have developed following cross-species transmission, during which the virus mutated to a form transmissible between humans at the beginning of the last century somewhere near the African country that is now called the Democratic Republic of Congo.
Its existence was not confirmed and documented by Western medicine until the 1980s, however.
Plantier and colleagues say they expect the gorilla version of the HIV version to show up in other locations.
Its discovery highlighted the continuing need to monitor closely for the emergence of new HIV variants, and demonstrated that HIV evolution was an ongoing process.
New strain of HIV found in France
