Scenes of crime investigators continued to search the home of 59-year-old Michael Snelling on Burnholme Grove in York and a property in Hollywell Road in North Shields believed to belong to his elderly mother, who now lives in a care home.
Sniffer dogs were brought into the homes and further items removed for forensic analysis.
Mr Snelling was a former York University laboratory technician who more recently held a position in a local mental health charity, York Mind, after leaving the university’s biology department last year.
He was arrested at the Tyneside property on suspicion of murder on Tuesday (May 13) and a car was also seized at the address. He has not been charged by police and was released on conditional bail on Wednesday, May 14.
Ms Lawrence went missing in York in March 2009. She was last seen after leaving work at Goodricke College, part of York University, on the afternoon of March 18.
Her family came from Darlington and later moved to Malton, North Yorkshire, where she was brought up.