Donald Trump's adviser Kellyanne Conway is being protected by the Secret Service after receiving death threats, as it was alleged she punched a man at the inaugural ball.

The White House counsellor said Trump's security detail began looking out for her after she received suspicious "white substances" at her home.

"Because of what the press is doing now to me, I have Secret Service protection," she told Fox News' Sean Hannity. "We have packages delivered to my house with white substances. That is a shame."