FBI: 'No Evidence' LA Metro Terror Threat Credible

The tip may have come from an anonymous caller behind previous false claims.

Officials now believe the tip may have come from an individual who has made previous reports that turned out to be false.

"Based on significant similarities, law enforcement partners also believe the anonymous caller may have, on a previous occasion, reported threats that did not materialize," the official said.

The tip, called in anonymously by an individual in Australia, caused local and federal law enforcement to deploy security measures that included large water-filled barriers, a bomb-sniffing dog and heavily armed Los Angeles County sheriff's deputies at the city's Universal City Metro station, according to KABC.

Any individual who knowingly provides false threat information to law enforcement is subject to prosecution, the FBI warned.