Mark Field has been suspended as a minister after TV footage showed him grabbing a female Greenpeace activist at a black-tie City event.
Mr Field, Foreign Office minister for Asia and the Pacific, has said he regrets the incident at the chancellor’s Mansion House speech.
He said he had been “genuinely worried” she may have been armed.
Mr Field was filmed forcibly removing the woman after protesters interrupted the speech.
A Number 10 spokeswoman said: “The prime minister has seen the footage and she found it very concerning.
“The police have said they are looking into reports over this matter and Mark Field has also referred himself to both the Cabinet Office and the Conservative Party.
“He will be suspended as a minister while investigations take place.”
On Thursday evening climate change protesters disrupted the beginning of Chancellor Philip Hammond’s annual Mansion House speech about the state of the UK economy.
Activists – dressed in suits, red dresses and sashes with “climate emergency” written on them – entered the room. Greenpeace said they wanted to deliver a speech on the failure of the current system.
Footage shows Mr Field getting out of his seat and stopping one female protester by pushing her against a column and marching her out of the room.
He later told ITV News that guests had “understandably felt threatened” and he had “instinctively reacted” when a protester rushed past.
“There was no security present and I was for a split second genuinely worried she might have been armed.
“As a result I grasped the intruder firmly in order to remove her from the room as swiftly as possible.”
He added: “I deeply regret this episode and unreservedly apologise to the lady concerned for grabbing her but in the current climate I felt the need to act decisively to close down the threat to the safety of those present.”
But his actions attracted widespread condemnation and Conservative Party chairman Brandon Lewis had said it was “very hard to defend” the footage and pledged an investigation.
City of London Police said they were looking into a “small number” of third-party reports of an assault at the Mansion House event.
The news source is www.bbc.com