The investigation is in part about his finances, sources told ABC News.
Denaturalization - the process of revoking citizenship from a naturalized US citizen - is rare and can only occur in federal court.
The post came hours after the acting attorney general committed to Congress that DOJ was scrapping plans for its "Anti-Weaponization Fund."
"We are not moving forward with the fund, period," Blanche said.
The Department of Justice has launched a criminal investigation into E. Jean Carroll, the former Elle magazine columnist who accused Trump of sexual assault, sources say.
Former President Joe Biden filed suit against the Justice Department to block the release of recordings and transcripts tied to a special counsel probe.