The police officer arrested on suspicion of the murder of Sarah Everard has been rushed to hospital with a head injury.
Wayne Couzens, 48, is being treated in hospital for the injury sustained while in custody, the Met Police said.
The force said the suspect, who is a serving Met Police officer, has since been returned to a station.
A Met Police spokesman said the suspect had been taken to hospital with a head injury and had since been discharged back into custody.
The spokesman 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."
Couzens is being held on suspicion of the kidnap and murder of the 33-year-old marketing manager who went missing in Clapham, south London, last Wednesday.
Miss Everard had been walking home to Brixton after visiting a friend's in Clapham.
She made a short phone call to her boyfriend, and was last seen on CCTV as she walked toward Tulse Hill at around 9.30pm.
Her worried friends and family led a desperate missing persons campaign to find her.
Officers searched through ponds and bins in Clapham and Brixton as they carried out fingertips searches of south London's streets.
They carried out searches at Couzens' home in Deal, Kent.
But police investigating Miss Everard's disappearance last night said they had found human remains in woodland in Ashford, Kent.
The force said the identity of the remains had not yet been confirmed and the process would take "some time."
Couzens, a member of the Parliamentary and Diplomatic Protection Command, continues to be held in London.
A woman in her 30s has also been arrested on suspicion of assisting an offender.
Met Police Commissioner Dame Cressida Dick yesterday said the force was "utterly appalled" that one of their own had been arrested.
She added that the case had sent "waves of shock and anger through the public and through the whole of the Met."
Dame Cressida added in the televised addresss on Wednesday evening: “Sarah’s disappearance in these awful and wicked circumstances is every family’s worst nightmare.
“I know Londoners will want to know that it is thankfully incredibly rare for a woman to be abducted from our streets.
“But I completely understand that despite this, women in London and the wider public - particularly those in the area where Sarah went missing - will be worried and may well be feeling scared.”
