Towards the end of his bitterly-fought presidential battle, Donald Trump vowed to appoint a special prosecutor to probe Hillary Clinton’s use of a private email server. His promise delighted his supporters who routinely spent much of their time at his rallies chanting “Lock her up”.

But the President-elect appears to have backed away from this proposal, the latest in a series of areas where he has indicated a reverse of course from the rhetoric and slogans he delivered on the campaign trail.

On Tuesday, as Mr Trump remained holed up in Trump Tower in New York as he continued to put together a team for his administration, senior adviser Kellyanne Conway said he would not pursue an investigation into either the former secretary of state’s use of an email server, or her charitable foundation.

“I think when the President-elect, who’s also the head of your party, tells you before he’s even inaugurated that he doesn’t wish to pursue these charges, it sends a very strong message, tone, and content,” Ms Conway told MSNBC.

Ms Conway said Ms Clinton, who won the popular vote by more than 1.5m votes, “still has to face the fact that a majority of Americans don’t find her to be honest or trustworthy”. But she said anything Mr Trump can do to help her heal, “then perhaps that’s a good thing to do”.

President Obama suggests Hillary Clinton didn't work as hard on campaign trail as he did

“Look, I think he’s thinking of many different things as he prepares to become the President of the United States, and things that sound like the campaign are not among them,” she said.

The announcement represents a significant break from a major campaign promise.

At the second presidential debate in early October, Mr Trump threatened Ms Clinton, saying that “if I win, I am going to instruct my attorney general to get a special prosecutor to look into your situation”.

In in his sole television interview since becoming President-elect, Mr Trump said he was unsure whether he would proceed with a probe.

“I’m going to think about it,” he told CBS. “I feel that I want to focus on jobs, I want to focus on healthcare, I want to focus on the border and immigration and doing a really great immigration bill.”

He said the Clintons “did some bad things”, but that ultimately they were “good people”.

“I don’t want to hurt them, I don’t want to hurt them,” he said. “They’re, they’re good people. I don’t want to hurt them.”

The FBI investigated allegations that Ms Clinton’s use of a private email server may have been a criminal offence. It concluded this summer that while she and her staff had been “extremely careless”, it did not amount to criminal behaviour.