A 49-year-old man has been arrested at a Southwark address where detectives found human remains whilst searching the property in connection to a Met Police officer reported missing earlier this week.
Police were called at 1.07pm on April 7 to an address on the Peabody Estate, Southwark Street where remains were found.
The man is now in police custody and officers have said it is a "significant development" in the search for the Westminster PC.
Although they were unable to make a formal identification, Gordon's family have been informed.
The Metropolitan police said it is "devastating news for all all those involved in the search for Gordon."
A spokesperson for the Met said: "His family are being supported by specially trained officers and his colleagues have been briefed.
"Our work at that scene is crucial to ensure we capture all available evidence and this may take some time.
At this stage we will not speculate any further on what may have happened or possible motive.
A post-mortem will be held in due course, and until that has taken place we will not speculate on the cause of death."
59-year-old Gordon, from Greenhithe in Kent, was last seen on April 1 in the London Bridge area.