Donald Trump threatened that Nikki Haley would be “under investigation” if she beat him in the Republican primary after defeating her in New Hampshire.

       The former president appeared to threaten his former UN ambassador after she vowed to continue her fight for the 2024 GOP presidential nomination.

       “Just a little note to Nikki, she is not going to win, but if she did she would be under investigation by those people in 15 minutes. I could tell you five reasons why already, not big reasons, little stuff that she doesn’t want to talk about, but she will be under investigation in minutes,” said Mr Trump to a crowd of his supporters on Tuesday night.

       “And so would Ron have been, but he decided to get out.”

       Mr Trump, who is the first and only former or sitting president to be criminally charged, faces a total of 91 felony counts across his four criminal indictments by state and federal prosecutors. He has pleaded not guilty to all charges against him.