Following his involuntary detention by police last week, Brad Parscale, US President Donald Trump's former campaign manager, has stepped down as a senior adviser, saying that he has sought help for the "overwhelming stress" on him and his family, a media report said.

"I am stepping away from my company and any role in the campaign for the immediate future to focus on my family and get help dealing with the overwhelming stress," Politico quoted Parscale as saying in a statement on Wednesday.

On Sunday, the 44-year-old was detained by police and hospitalized over suicidal threats he made at his residence while holding a gun.

Also in a statement provided to Politico news on Wednesday, Parscale's wife, Candice, also denied that he physically abused her.

"The statements I made on Sunday have been misconstrued, let it be clear my husband was not violent towards me that day or any day prior," she was quoted as saying.

According to the statement she gave to the police, Candice Parscale fled their residence in Fort Lauderdale after watching her husband cock a handgun.

Police reports and video footage depicted a chaotic situation, with Candice Parscale telling law enforcement that her husband was "ranting and raving".

Parscale's resignation came two months after he was demoted as campaign manager in July as the President's poll numbers dipped, said the Politico news report.

In a statement to CNN after Parscale's hospitalisation, Tim Murtaugh said: "Brad Parscale is a member of our family and we all love him. We are ready to support him and his family in any way possible."