Attorney General of New Hampshire John Formella (R) announced February 6:
[AG's office] has identified the source of the January 21, 2024, robocalls received by numerous New Hampshire residents, which played a message with what appeared to be an AI-generated voice clone of President Biden’s voice, and which encouraged recipients not to vote in the January 23, 2024, New Hampshire Presidential Primary Election
The source was identified as a Texas company called Life Corporation and a man named Walter Monk.
The call appeared to be made by using ElevenLabs (free test version I have used, quite good) AI voice software which has suspended the account in question.
The Industry Traceback Group a firm created by the telecom industry assisted in determining communication services were provided to Life Corporation by Lingo Telecom, who has suspended services to Life Corporation.
The FCC has ordered Lingo to stop providing services to illegal robocall traffic and said it may order other providers to block Lingo’s traffic if it doesn't.
According to the NYT a subsidiary of Life Corporation known as Voice Broadcasting Corp. identifies Monk as it's founder. It has received payments from both democratic and republican congressional candidates as well as the state GOP of Delaware.
Monk may be hiding out in his office (a man was seen by NBC-5 at the address) but so far hasn't commented.