The US State Department said it is investigating an imposter who used artificial intelligence to impersonate Secretary of State Marco Rubio and contact three foreign ministers.The "unknown actor" is alleged to have used an artificially-generated voice of Rubio to contact officials via the Signal messaging app,

The recipients of the scam messages, which were sent by text, Signal and voice mail, were not identified in the cable, a copy of which was shared with the Associated Press.

A person or people imitating the secretary of state used artificial intelligence to send text and voice messages to foreign diplomats and U.S. officials, the department said in a cable to employees.