A police officer who hit a vulnerable teenage girl with a baton "at least 30 times" has been sacked.
Metropolitan Police officer Benjamin Kemp, based at north east command, was dismissed without notice following a disciplinary hearing by the Independent Office for Police Conduct (IOPC).
During the hearing, the panel heard a 17-year-old girl, who has learning disabilities, ran off from a group on an escorted walk in Newham after becoming distressed on 8 May 2019.
She was near a main road and police were called by a concerned member of the public, and she also flagged down a passing police car.
After she told officers that she was a vulnerable child with mental health problems, she agreed to get in the police car but then got out of it.
The IOPC said PC Kemp attempted to handcuff her, but when this was unsuccessful he then used CS spray – an incapacitant – less than a metre from her face.
"Within seconds he started using his baton and then struck her several times," it said.
When another police unit arrived, the girl was immediately tasered by an officer from that vehicle, and she was then struck several times more with the baton by PC Kemp, handcuffed and put into a police van.
In total she was struck at least 30 times, the IOPC said.
An investigation followed after a complaint was made by NHS workers and the mother of the teenager from east London.
The watchdog said the girl was black but there was no indication that racial discrimination played a factor in this case.
IOPC regional director Sal Naseem said the force used by police "would be shocking to most people".
He added: "The disciplinary panel also found PC Kemp had behaved in a manner which lacked self-control and did not take into account the vulnerable status of the teenager, who appeared very frightened.
"The poor communication by this officer got the incident off to a bad start and, once he started to use the baton, he was unable to change tack."
Chief Superintendent Richard Tucker, who leads policing for north east command, described the use of force by PC Kemp as "utterly inappropriate".
He said: "He over-reacted, used excessive force in a very disproportionate manner and was unprofessional.
"For that he has been held to account, and has been rightly dismissed from the service. I can assure you his actions are not representative of how we deal with situations like this in Newham and across London."
The IOPC said the six-month investigation found the officer who used the Taser "had no case to answer for use of force" but there was a case for misconduct and he received "management action" in August last year.
It said the officer showed a lack of respect to the girl and her health carer, who later arrived at the scene.