British police suspended a sergeant from the London Metropolitan force on Wednesday after video footage showed him lashing out at a woman in a demonstration during the G20 summit in the capital.
The footage, aired on the website YouTube, showed a woman protester taunting an officer, who appeared to retaliate by striking her across the face with his hand.
It is the second incidence of apparent police violence during the G20 protests to be caught on camera.
"The officer has been identified and suspended pending further investigation," police said in a statement. It said the officer was a sergeant in the Territorial Support Group -- a police team trained to deal with public order events and potential violence.
The statement described the video as one which showed a "police officer using force against a protester".
The footage, filmed close to the Bank of England on April 2 during the London summit of the Group of 20 large economies, appeared to show the officer drawing his baton and hitting the woman on the legs moments after he had struck her face.
When the film first came to light late on Tuesday, the Metropolitan Police said the officer's actions raised immediate concerns.
"Every officer is accountable under law, and fully aware of the scrutiny that their actions can be held open to," it said in a statement. "The decision to use force is made by the individual police officer, and they must account for that."
It said it had referred the incident to the Independent Police Complaints Commission (IPCC) -- a police watchdog which is already investigating the death of a man police hit in the G20 protests on April 1.
Last week a police officer was suspended pending further investigations after being caught on camera pushing newspaper seller Ian Tomlinson to the ground. Tomlinson, 47, died of a heart attack after collapsing later in a nearby street.
He was not involved in the demonstrations but was on his way home at the time. The incident was captured on video taken by a New York fund manager and later aired on a newspaper website.
Additional video footage from Channel 4 television also appeared to show an officer striking him with a baton in the moments before he was pushed.
Güncelleme Tarihi: 15 Nisan 2009, 14:27