A man is being questioned on suspicion of murder after the remains of a veteran police officer were found on a housing estate.
The 49-year-old suspect was arrested at a property in Southwark, south London, on Thursday where the remains of Pc Gordon Semple, 59, were also found.
The officer of 30 years was last seen at 3pm on Friday on CCTV near London Bridge, a short distance from the property on the Peabody Estate.
Officers are continuing a "vital search for evidence" at the scene which will take "some time" to complete, Scotland Yard said.
Metropolitan Police Commander Alison Newcomb said: "This is a very sad day for Gordon's colleagues.
"There are many officers who have served with Gordon in London during his 30-year career who will acutely feel his loss."
Pc Semple left his home in Greenhithe, Dartford, to go to work in Westminster on Friday, and on that same day visited the Shard in Southwark. He left there at 12.30pm and was last seen on CCTV about two and a half hours later.
Ms Newcomb, commander of the territorial policing unit, said: "Yesterday afternoon we were called by a member of the public to an address on the Peabody Estate, Southwark Street.
"At that address a man was arrested and human remains were discovered.
"Due to the condition of those human remains it will take some time for the cause of death to be established and for formal identification to take place.
"At this point I do not wish to speculate on what has happened."
She appealed for anyone with information to get in touch with the force.