Police in Britain were beginning a drilling and digging operation today in the basement of a former home of serial killer Peter Tobin.
The property in Station Road, Portslade, East Sussex, is one of two former homes of Tobin being searched by police.
The other is in in Marine Parade, Brighton. Tobin lived at the houses during the 1980s.
Tobin is serving three life sentences for killing Angelika Kluk, Vicky Hamilton and Dinah McNicol.
Sussex Police started their searches at the two addresses last Monday, convinced he claimed more victims as he lived across Britain under different names and trawled the motorways for vulnerable female hitch-hikers.
A Sussex Police spokesman said work in the basement of the Portslade property will start at 9am today. It is being carried out on a Sunday to minimise disruption to nearby shops.
Neighbours of the house had letters delivered to them today warning them of the operation.
Officers already ruled out any crimes linked to a Victorian well found in the garden of the Station Road house. It was excavated to around 10ft last week by a specialist search unit.
Teams of police and archaeologists are continuing their searches at the property and at the address in Brighton.
Tobin was told last December that he would die in jail after he was convicted of strangling 18-year-old Miss McNicol.
The former church handyman was already serving life terms for the murders of 15-year-old Vicky and Angelika Kluk, 23.
Police discovered the remains of Vicky and Miss McNicol buried in the garden of a house in Margate, Kent, to which Tobin moved in March 1991.
Police said the searches behind flats in Marine Parade and a hairdressing salon in Station Road, Portslade, could continue for a month.
The Station Road hairdressing salons were once a cafe, Ye Olde Tea-room, run by Tobin in 1988 with Cathy Wilson, who later became his wife and with whom he had a son.
Neighbours recall Tobin doing a substantial amount of DIY on the property as he converted it from a junk shop and cleared the garden.
Marine Parade is a large housing association block of flats which backs on to a small area of grass and concrete paving.
Investigators refused to go into detail about why police were targeting the two properties or what cases they may be linked to.
Police responsible for the inquiry are believed to have narrowed down their review of unsolved murders and disappearances linked to Tobin to nine cases.
These may include the murders of art student Jessie Earl, 22, whose body was found in 1989, and Louise Kay, 18, who disappeared in Eastbourne in 1989. Her body was never found.
There are several other possible cases including law student Pamela Exall, 22, who vanished in Norfolk in 1974, schoolgirl Patricia Morris, 14, who went missing in Essex in 1980, and Suzanne Lawrence, 14, last seen in Essex in 1979.
Other cases include the murders of three women in Glasgow in 1968 and 1969 by a figure nicknamed “Bible John”, and the deaths of schoolgirls Karen Hadaway, 10, and Nicola Fellows, nine, in Brighton in October 1986.
Detectives attempted to speak to Tobin in prison about the latest developments but he refused to talk to them, and they remain keen to unravel further details of his life, particularly where he lived in 1977 and 1978.
Police said Tobin used several aliases, mostly variations of the same name, during around two decades in Brighton from 1969 when he lived at homes in Dyke Road, Regency Square, Eastern Street and Chadborn Close.
The search teams included members of the Home Office’s scientific support branch and officers from the Metropolitan Police as well as Sussex Police experts and archaeologists from University College London.
The itinerant serial killer lived in several other towns and cities, including Glasgow, and Havant, Hampshire. Police said he may have owned more than 100 vehicles and used 40 aliases.