A report by the watchdog, Miviludes, published on Wednesday said the picturesque village near Carcassonne should be monitored in the run-up to December 21, 2012, when many believe the world will end according to an ancient Mayan prophecy.
Miviludes was set up in 2002 to track the activity of sects, after a law passed the previous year made it an offence to abuse vulnerable people using heavy pressure techniques, meaning sects can be outlawed if there is evidence of fraud or abuse.
Surrounded in legend for centuries, Bugarach and its rocky outcrop, the Pic de Bugarach, have attracted an influx of New Age visitors in recent months, pushing up property prices but also raising the threat of financial scams and psychological manipulation, Miviludes said in its report.
"I think we need to be careful. We shouldn't get paranoid, but when you see what happened at Waco in the United States, we know this kind of thinking can influence vulnerable people," Miviludes president Georges Fenech told Reuters.
Waco, Texas, made headlines in 1993 when federal agents raided the headquarters of the Branch Davidian movement, led by David Koresh, leading to a 50-day siege.
The building was burnt down when agents eventually tried to force their way in, leaving some 80 people dead.
Bugarach, with a population of just 200, has long been considered magical, partly due to what locals claim is an "upside-down mountain" where the top layers of rock are older than the lower ones.
The Internet is awash with myths about the place -- that the mountain is surrounded by a magnetic force, that it is the site of a concealed alien base, or even that it contains an underground access to another world.
And now many have seized on it as the ultimate refuge with Doomsday rapidly approaching.
Alerted to an influx of visitors by the mayor of Bugarach, Fenech said he recently visited the area, and found six settlements in the surrounding countryside set up by members of the American Ramtha School of Enlightenment.
Other "gurus" and messianic groups have been organising fee-paying conferences at local hotels, according to Fenech. "This is big business," he told Reuters.
Aside from the risks in Bugarach, the Miviludes report also warned of the danger of increased activity by Apocalyptic groups across France in the run-up to 2012, particularly in the wake of recent disasters which could be interpreted as omens.
Climate and environmental fears, anxiety over pandemics after the 2009 swine flu outbreak, and the earthquake disaster in Japan are all reinforcing the idea of the Mayan calendar, Fenech said.
Among the groups highlighted in the report, the Ramtha movement is said to be focussing on southwestern France to spread its message, the report said.
Founded by J.Z. Knight, the group claims to follow the mystic teachings of Ramtha, a Lemurean warrior who fought the residents of the mythical Atlantis 35,000 years ago, and is said to have discovered the secret of immortality.
Other groups being watched include the Raelians, founded by a former sports-car journalist who claims to have had repeated encounters with aliens.
The report says its aim is not to stigmatise movements but to inform the public about "groups or individuals whose doctrine or discourse follows an "end-of-world" theory."
(Editing by Paul Casciato)