Detectives investigating the disappearance of a serving police officer have arrested a man on suspicion of murder after discovering human remains at a property in south London.

PC Gordon Semple, 59, left his home in Greenhithe in Dartford, Kent, on 1 April to go to Westminster, where he works for the city council’s antisocial behaviour team. His partner reported him missing after he failed to return home.

A 49-year-old man was arrested at an address in Southwark on suspicion of murder and is in police custody, Scotland Yard said, after police were called to the property on Thursday.

“This is obviously a significant development, and we have informed Gordon’s family,” a statement from the Metropolitan police said. “We are unable to make formal identification at this stage, but this is devastating news for all those involved in the search for Gordon.”

The last known sighting of Semple was at 3pm on Friday when he was seen on CCTV on Great Guildford Street near London Bridge, half a mile from the Shard. He had left the 95-storey tower at about 12.30pm after an on-duty meeting at the Shangri-La hotel in the building.

Gordon Semple disappeared on Friday. Photograph: Metropolitan Police/PA

Detectives had been trying to establish where the Scottish-born officer was in the hours between his departure from the Shard and the last sighting of him on CCTV.

Members of his family, some of whom live in Inverness, set up a Facebook appeal page but were asked by the Met not to talk to the media.

Semple’s brother Ronnie, an Inverness taxi driver, told the Guardian the experience had been particularly difficult as they felt so far away from London. He declined to comment further.

His family are being supported by specially trained officers and his colleagues have been briefed, Scotland Yard said.

Semple’s niece Kerry Nicholas told Kent Online on Wednesday: “We are very concerned. It’s very out of character for Gordon not to get in touch with anybody. He had been at a meeting in the Shangri-La. He’s very outgoing, sociable and friendly. He’s a happy-go-lucky kind of guy.

“Nothing like this has happened before. There’s absolutely no reason for him to go missing. At the moment we are just concerned about his wellbeing.”

The Met said a postmortem will be held, adding that the force will not speculate on the cause of death.