Police investigating Suzy Lamplugh's disappearance are preparing to excavate the garden of a home previously owned by the prime suspect's mother.
Miss Lamplugh was declared dead, presumed murdered, after going missing aged 25 in 1986, having left her west London offices to meet a mystery client known only as Mr Kipper.
The Metropolitan Police on Tuesday were leading the search at a Birmingham semi previously belonging to suspect John Cannan's mother.
The convicted killer, who is currently in jail for rape and murder, was named as the prime suspect by police in 2002 and her death has remained one of the UK's most notorious cold cases.
Nobody has been convicted.
Former police officer Neil Thomas told Julia Hartley-Brewer that "prisoners serving with John Cannan in prison say the body is buried in his mother's garden in Sutton Coldfield."
'If something is found, it's closure for the family'
Police outside the property in Sutton Coldfield. Image: PA
Insurance marketer Phillip Carey said he purchased the home in Shipton Road, Sutton Coldfield, from Sheila Cannan in 1992.
"From our point of view, we bought the house 26 years ago, from the suspected person's mother, Sheila," the 52-year-old told the Press Association.
"We knew who she was, we became aware who she was as we went through the relationship, and obviously it was high profile at the time."
It is not the first time police have been at the family home, the father-of-two said, with officers visiting the garden over several months about 15 years ago.
They did not dismantle, dig or remove anything during searches, as far as Mr Carey was aware.
"Either [the property] is eliminated from it [the investigation] entirely or, if there is something found, it's closure for the family, and this tragic story can come to an end,” he added.
Current occupants 'not connected'
Jim Dickie, the detective superintendent leading the investigation between 2000 and 2006, confirmed his officers did not dig or perform an "extensive" search of the home.
"We had no evidence or intelligence to lead us to believe that John Cannan may have secreted Suzy's body there," he told the BBC.
At the scene, specialist forensics scientists from the private company Alecto arrived carrying equipment throughout the morning.
What sounded like an angle grinder was used in the garden, with dust billowing over the adjacent alleyway.
A blue tent was erected over what is believed to be a former garage in the rear garden of the property, the roof of which is just visible beyond the police cordon.
The Met, being supported by West Midlands Police officers, stressed that the current occupants of the property are in no way connected to the investigation.
Suspect denies murder
Suzy Lamplugh. Image: PA
Cannan was jailed for life in 1989 for the rape and murder of Bristol newlywed Shirley Banks.
On the day of her disappearance, witnesses reported seeing Miss Lamplugh argue with a man outside a property in Shorrolds Road, Fulham.
Three days earlier, Cannan had been released from a hostel at Wormwood Scrubs Prison, where he had been serving a six-year sentence for rape.
He bore a strong resemblance to an e-fit of the abductor and, according to reports, he was nicknamed Kipper while serving his earlier sentence.
In 2002, claims were reported that Cannan had buried Miss Lamplugh's body under his mother's patio in the West Midlands.
A Scotland Yard spokesman at the time said the theory was "something we are currently considering", but did not confirm reports they planned to excavate the garden in the coming days.
On Tuesday a spokeswoman for the force declined to comment on why the dig was to take place now, citing the sensitivity of the operation.
Cannan, now 64, has been questioned several times over the murder and has denied the allegation.