The policeman, charged with the murder of Sarah Everard, was hospitalized for the second time to be treated for a new head injury in custody.
City police said the incident happened on Friday.
A spokesman for the force said Couzens was “being watched by officers” when he sustained a second head injury within 48 hours.
The spokesman said: “The suspect was rushed to hospital on Friday March 12th for treatment for a head injury sustained while in custody in a cell.
“He was monitored by officers and received immediate first aid.
“He was released and taken into custody the same day.”
It comes a day after he was treated for an injury he sustained alone in his cell on Thursday.
He is due to appear in Westminster Magistrates Court on Saturday.
48-year-old police officer Wayne Couzens was accused Friday night of kidnapping and killing Ms. Everard, who was missing on March 3 on her way home from a friend’s apartment in south London.
Ms. Everard is said to have walked through Clapham Common to her home in Brixton – a journey that should have taken about 50 minutes.
Durham University paid tribute to “Beloved Graduate” Sarah Everard, who studied geography at St. Cuthbert’s Society.
In a statement, Vice Chancellor Professor Stuart Corbridge said: “Sarah was a popular and lively member of our college community and kept a large friendship group from Durham University.”
Met police said Couzens worked for the force for about two and a half years after joining in September 2018.
A statement said: “In the interest of clarity about these extraordinary events, we are publishing further details of Couzens’s employment with the Metropolitan Police Service.
“Wayne Couzens joined MPS on September 10, 2018. His first posting was to the South Area, where he joined a response team that covered the Bromley region.
“He then moved to the Parliamentary and Diplomatic Protection Command on February 1, 2020, where he mainly performed uniformed patrol duties in diplomatic premises, mainly in a number of embassies.”
The Met said the investigation would be continued and led by specialist detectives with the assistance of Kent Police.
Police said a woman in her thirties arrested Tuesday on suspicion of assisting a perpetrator was released on bail to return to a police station in mid-April.
Nick Ephgrave, Assistant Commissioner of the City Police, told Scotland Yard on Friday evening: “I would like to take this opportunity to pay tribute to Sarah’s family for their steadfastness and forbearance in what may be the most difficult days.
“Our thoughts stay with you as this matter progresses.”
In a message of support tonight, Archbishop of Canterbury Justin Welby said: “Testimony from testimony of women over the past few days has shown us something we have known and ignored for far too long: the profound effects of male violence, intimidation and sin Harassment, Sexism, and Abuse Against Women. “
Rosemary Ainslie, CPS chief of specialty crimes, said tonight, “Following a transfer of evidence by the Metropolitan Police in connection with Sarah Everard’s death, the CPS has authorized police to charge Wayne Couzens with murder and kidnapping.
“He will appear for his first hearing in Westminster District Court tomorrow (March 13th).
“The role of the CPS is not to determine whether a person is guilty of a crime, but rather to make fair, independent, and objective assessments of whether it is appropriate to bring charges to a court to investigate.
“The criminal case is now active and nothing should be published that could compromise the defendant’s right to a fair trial.”