The Metropolitan Police officer suspected of kidnapping and murdering Sarah Everard has been taken to hospital for a head wound sustained while in custody.
Scotland Yard said the suspect, who is in his 40s, was treated, discharged and returned to the police station where he is being held.
He was found collapsed and unconscious in his cell on Thursday after suffering serious head wounds, according to The Sun.
The Met said: "The suspect was taken to a hospital for treatment to a head injury sustained while in custody.
"He has since been discharged and returned to custody. We are not prepared to discuss further."
Met Commissioner Dame Cressida Dick said on Wednesday night that human remains - which have not yet been identified - had been found in an area of woodland in Ashford, in Kent, by detectives investigating Ms Everard's disappearance.
Wayne Couzens, a serving police officer in the Parliamentary and Diplomatic Protection Command, had earlier been arrested on suspicion of kidnap and murder.
The police force said the arrested officer’s main job was uniformed patrol of diplomatic premises, but would not specify where he had worked. He was not on duty at the time of Ms Everard’s disappearance.
Reports say he was working a 2pm to 8pm relief shift at the US Embassy in Nine Elms, south-west London, which is situated around three miles from where she was last seen.
The diplomatic protection squad is responsible for guarding the parliamentary estate including Downing Street and the Palace of Westminster, as well as embassies in London.
The officer was also arrested over a separate allegation of indecent exposure.
A woman in her 30s has been arrested on suspicion of assisting an offender.
