Neighbours say they spotted a Land Rover containing two men watching the property for two hours before around 20 officers raided the house.
A shirtless Couzens was led from the house in handcuffs with one witness saying: 'He looked very calm - just walked out'.
Today it was claimed that Couzens worked a 2pm to 8pm shift at the US embassy on the day his alleged victim vanished 'into thin air'. The building he was guarding is less than three miles from where Miss Everard was last seen at 9.30pm as she walked home to Brixton on March 3.
Met Police operations will continue at the woods and in Deal for the rest of the week.
A Kent Police spokesman said: 'Over the next few days, the Met Police will continue to carry out activities across the area whilst their enquiries progress.'
A car linked to Couzens - thought to be a hire vehicle - was reportedly picked up on a motorist's dashcam near to the spot where Sarah disappeared last Wednesday.
One source told MailOnline: 'If they identified his car from the bus, they will have been able to see him driving all the way home on London and Highways England's network of cameras.
'If she was in the car, they will have footage of him with her'.
Detectives also probe whether the suspect used his warrant card to lure her into his car after leaving work guarding the nearby US Embassy, it emerged today.
Scotland Yard are also said to be investigating whether Couzens, 48, used the current Covid-19 lockdown rules to stop the missing woman as she walked home to Brixton from her friend's home in Clapham, south-west London on the evening of March 3.
Police have ramped up their operation at the rural crime scene this afternoon, setting up a mobile headquarters and sending in a diving unit as well as more officers in multiple riot vans.
Forensic officers in blue boiler suits were seen entering the woods with tripods, cameras and possibly equipment to scan the soil.
MailOnline believes that the woods where the remains were found were known to him because Couzens' Ukrainian wife and their two children had visited for walks.
Couzens was working at the US Embassy just three miles from where Sarah vanished and knocked off work around 90 minutes before she was last seen.He was working there as an armed guard.
Aerial footage shot by the BBC shows the back of the garden complete with a pool apparently covered over by investigators
Police have today expanded their presence at the site in Ashford where human remains were found last night, including a mobile HQ (pictured being dropped into place) and a diving unit.
Officers made the horrifying discovery at the disused Great Chart Golf & Leisure Country Club near Ashford (pictured today)
Couzens' home in Deal is surrounded with metal walls and is swarming with forensics officers
Police also searched the suspect's family's former garage in Dover, which is now disused and abandoned
There is so much information to unpack here. Much more at link:
Sarah Everard: Police officer arrested over 'kidnap and murder' found in cell with head injuries'