Josh Lowth, 33, is the boyfriend of missing Sarah Everard, the woman seen walking between Clapham Junction and Brixton. The couple spoke for around 15 minutes on the phone before Sarah's disappearance
A woman was also arrested at the same address on suspicion of assisting an offender
Footage from a doorbell camera last captured images of Miss Everand as she walked along the A205 Poynders Road towards Tulse Hill at around 9.30pm.
Officers yesterday sealed off a block of flats as they began a forensic investigation close to where the Durham University graduate was last seen.
A short stretch of the South Circular was closed along Poynders Road, where the block of flats are, between Cavendish Road and Rodenhurst Road.
Forensic officers were seen looking through hedges and along the street as they searched for any evidence that could aid them in their search.
The Met also yesterday released two new images of the missing woman.
Met Police tweeted on Tuesday: 'Were you driving in the Poynders Road area after 9.30pm on Wednesday 3rd March?
'PLEASE check and double check your dash and door cams for footage.'
The search continued after it was revealed Miss Everard spent a quarter of an hour on the phone making plans to see her boyfriend Josh Lowth the following day, before her mobile was either switched off or ran out of battery.
Mr Lowth, 33, whose LinkedIn says he is Marketing Director at MA Exhibitions, later raised the alarm to police when she failed to meet him as she had arranged, her aunt confirmed.
Speaking at Mr Lowth's family home in Sidcup, Kent, his father Chris told MailOnline: 'We are concerned, like everybody is. We really, really want to see her back.'
'The whole family is obviously very worried about her and just wants her home safely.
'We're all pulling together and praying that this awful situation is quickly resolved. We want to thank the media for all their help.'
Forensic teams from Met Police were outside Poynders Court along the South Circular this evening after Met Police raised a 100-metre cordon during the search for missing Sarah Everard
Her family and friends released a plea for her return, saying: 'Sarah, we are here for whenever you are ready'
Teams were seen looking through bushes outside the block of flats as locals looked on. Met Police has urged anyone who was in Poynders Road at around 9.30pm last Wednesday to get in touch
Forensic officers could been taking pictures of marked areas outside Poynders Court on Tuesday evening, as the search continues
Forensic officers were outside a block of flats in Poynders Road this evening, six days after Ms Everard disappeared last week
Mr Lowth shared a Facebook post appealing for anyone who knows where Miss Everand is to get in touch with police.
He wrote: 'Sarah is still missing. Please share this post to help us to find her. Today, more than ever, we miss our strong, beautiful friend.'
The 33-year-old is understood to have left her friend's house through a back gate onto the A205 South Circular at around 9pm on March 3.
She then began walking to her home address in Brixton, and should have returned home 50 minutes later.
Miss Everard was last seen on CCTV at around 9.30pm last Wednesday.
Her father Jeremy, 67, a professor of electronics at York University, and mother Sue, 64, a charity worker, are understood to have travelled to London from their home in York. They are being helped in the search by her sister Katie and brother James.
In a statement, the family said: 'With every day that goes by we are getting more worried about Sarah.
A poster is seen as police search teams work their way through the reeds in Mount Pond on Clapham Common
An appeal poster in Brixton, south London, for information on missing Sarah Everard, 33
Officers were carrying out door-to-door enquiries as they searched outside homes in Brixton for any trace of the missing marketing executive
Investigators believe Sarah walked across Clapham Common towards her home in Brixton, and was last seen on CCTV in Poynders Road before disappearing. Officers are searching outside homes in Brixton yesterday
Family say they are getting 'getting more worried about Sarah,' with each passing day, as officers were seen combing through hedges to spot for evidence yesterday
'She is always in regular contact with us and with her friends and it is totally out of character for her to disappear like this.
'We long to see her and want nothing more than for her to be found safe and well.
'We are so grateful to the police and all our friends for all they are doing.
'We are desperate for news and if anyone knows anything about what has happened to her, we would urge you to please come forward and speak to the police. No piece of information is too insignificant.'
Ahead of the arrests on Tuesday, Ms Goodwin, who is leading the investigation, said there was no information to suggest Ms Everard had 'come to any harm'.
She added: 'We've released two new images of Sarah as we continue to search for her.
'Please take a look at them and consider if you saw her on the night she went missing. I am interested in hearing from people who may have been in the area from 9.30pm onward.
'I want to remain clear that at this time we have no information to suggest that Sarah has come to any harm and we retain an open mind as to the circumstances.
'We share the wish of her family and friends to have her back safely with her loved ones.'
Police said they had received more than 120 calls from the public and visited 750 homes as part of their investigation into Miss Everard's disappearance.
While searches were carried out in Brixton earlier yesterday , officers in nearby Clapham have set up a 100-metre cordon outside a block of flats
Mr Lowth, 33, raised the alarm to police when his partner failed to meet him the following day as they had arranged. Officers have continued their desperate search for the missing woman, looking through bins outside homes in Brixton for any evidence that could help find her
In a statement, Sarah's family said: ''We are desperate for news and if anyone knows anything about what has happened to her, we would urge you to please come forward and speak to the police. No piece of information is too insignificant'
Ms Goodwin added: 'We have seized a number of CCTV recordings but we know that there are likely to be many more out there.
'Please, even if you're not sure, check your doorbell or CCTV footage just in case it holds a clue.
'I'm also asking delivery drivers or anyone with dashcam footage who would have been in the Poynders Road area at approximately 9.30pm on Wednesday to come forward.'
The investigation is being treated as a missing person's enquiry, but due to its complex nature it is being led by the Met's Specialist Crime Command.
Superintendent Kris Wright, from the Met's Central South Area Command Unit which covers Clapham, said on Tuesday: 'I know that Sarah's disappearance is weighing on people's minds and the local community is, of course, concerned about her and may even feel worried.
'I want them to know that they should expect to see more police officers on patrol in the area as we continue to search for Sarah and talk with the community. If you want to approach them about any concerns you have, please do so.
'We are here to support the community and we genuinely want to help in any way we can.'
Anyone who has seen Sarah or who has information that may assist the investigation should call the Incident Room on 0208 785 8244.
Information can also be provided to detectives using the Major Incident Portal or by calling Crimestoppers, anonymously, on 0800 555 111.