By Jacob Bogage and Andrew Goudsward

WASHINGTON, Oct 14 (Reuters) - The US Justice Department on Tuesday gave California officials 48 hours to review a list of alleged noncitizen voters or face legal action, according to two letters reviewed by Reuters, part of an unprecedented effort to find evidence ‌of voter fraud ahead of next month's elections.

The letters, written by acting Deputy Attorney General R. Trent McCotter and addressed to California Secretary of ‌State Shirley Weber and Los Angeles County Registrar-Recorder Dean Logan, say the Justice Department provided officials in Los Angeles County with a "password-protected thumb drive" with the names of people the federal government "believes are likely noncitizens" ​and were sent mail-in ballots from California.

The letters demand the state refuse to send ballots to those on the list until their citizenship status has been confirmed. Vo...