Two houses 100 miles apart are being searched by police after a man was arrested on suspicion of murdering missing university chef Claudia Lawrence.
A 59-year-old man, named locally as Michael Snelling, was arrested this morning at a house in North Shields, Tyneside, on suspicion of murdering Miss Lawrence, who went missing in York in March 2009.
Neighbours said his car was seized as police officers began a search of the semi-detached property.
Mr Snelling's home in York was also cordoned off, boarded up and subjected to a forensic search today.
North Yorkshire Police confirmed a man had been arrested on suspicion of Miss Lawrence's murder but stressed the chef had not been found.
It is understood that the house where Mr Snelling was arrested, in Hollywell Road, North Shields, is his mother's home.
Neighbours in York said he spent a lot of time at the property, in the area where he grew up. But, they said, he would return to York during the week for work.
They said he worked for some time as a lab technician at York University but recently started work for a mental health charity.
Hollywell Road resident Ronald Robinson, 81, said: "I think he was arrested here because his car pulled in last night. I think it would have been about 8am.
"His job was down there but he lives up here. He would come home every Friday for the football match.
"He would come back every weekend to take his mother to get the shopping in.
"She's in a home now for dementia but he made sure he kept her at home as long as he could.
"I've seen him grow up as I've lived here for 40 years."
A police van was parked outside the house tonight, with two police officers standing on the drive. Forensic officers were seen carrying boxes out of the property earlier.
People living near Mr Snelling's run-down semi in Burnholme Grove, York, said they were shocked about the police activity in their street.
Neighbours said he had lived in the house for more than 20 years.
Terry Ellis, who has lived in Burnholme Grove since 1961, said: "The first thing I saw this morning was when the police investigation car came up.
"I thought that maybe someone had broken in, because he's had someone break in before."
His neighbour, student Adam Wadsworth, 19, said: "I'm pretty shocked."
Another neighbour, Rita Harrison, said the area was "lovely" and "very quiet".
"Everyone's shocked," she said. "But they need to get to the bottom of it."
Mr Snelling's house is about half a mile from the small house where Miss Lawrence lived by herself in the Heworth area of York.
Police officers and white-suited forensic scientists could be seen coming and going from the property throughout the day.
This afternoon, contractors arrived to board up the doors and some of the windows and uniformed police cordoned off the property with tape.
The house, which has a drive, a garage and pebbled front garden, is about half-way down the cul-de-sac, which is a mixture of established families and students from the nearby York St John University. It has a small rear garden with a patio and lawn.
Miss Lawrence, who worked in a kitchen at York University, was 35 when she was reported missing by her father Peter on March 20, 2009.
She was last seen at around 3.05pm on March 18, walking back towards her home, and that night she spoke to both her parents on the phone.
It is thought something happened to her after she left for work early on March 19.
North Yorkshire Police launched a review of the investigation last year after a new major crime unit was established by the force. They have always said that detectives believe the chef had been murdered.
Last year, the new investigation team conducted a detailed, two month-long re-examination of Miss Lawrence's home.
And, in March, senior officers announced a series of new lines of inquiry on the fifth anniversary of the day she failed to turn up for work. The announcement coincided with a fresh appeal on BBC's Crimewatch.
They said the new forensic examination of her house uncovered the fingerprints of people who have not yet come forward.
They also found the DNA profile of an unknown man on a cigarette butt in the university chef's Vauxhall Corsa.
Police have said before that Miss Lawrence's mobile and rucksack have never been found.
A force spokesman said today: "Detectives investigating the disappearance of Claudia Lawrence have this morning arrested a 59-year-old man from York on suspicion of murder.
"Forensic examinations and searches are being conducted which are expected to be ongoing over a number of days. A car has also been seized as part of the inquiries.
"The investigation team would like to stress that Claudia has not been found.
"Police cannot rule out the possibility of further arrests in the future as the review continues.
"Claudia's family have been notified and are being supported by trained officers."
Miss Lawrence's father has mounted a five-year campaign to find his daughter.
At the anniversary in March, he discussed the "torture" his family had suffered through five years of not knowing what has happened to her.
Today, he told York's paper, The Press: "I'm very pleased they appear to be making progress by making this arrest."
Miss Lawrence's mother, Joan, told ITV News Calendar : "The police were on my doorstep not long after 8am. I was gobsmacked.
"I just had absolutely no idea. I had absolutely no idea about any of this but I've got to keep an open mind about it. To be quite honest, it hasn't sunk in yet."
Miss Lawrence's close friend, Suzy Cooper, said she always believed there would be progress in the case.
"I have always put my faith in the police," she said. "I never really doubted that."
The 49-year-old, who lives in York and works in accounting, said it had been impossible for her to move on in her life after her friend's disappearance.
"I have been trying to focus on my own life but Claudia has always been in my thoughts," she said.
Martin Dales, a friend and spokesman for Peter Lawrence, said: "Today has been an exacting day for Peter, his family and Claudia's friends as the news comes of the first arrest in the five years since she went missing and it is clear there is a long way to go in finding out what has happened to her.
"It is also clear that the renewed efforts of North Yorkshire Police since last autumn and the new information provided by the public could well be bearing fruit but we shall have to wait and see.
"It is vital that information continues to flow and it is to be hoped that the events of today encourage the public to keep coming forward to the police. They can be contacted on 101 and selecting North Yorkshire police if not in their area."