Diggers have begun work on an area of parkland which has been sealed off by police looking to solve the 21-year-old disappearance of a teenage girl.
Sarah Benford has not been seen alive since she went missing from a Northampton care home on April 6, 2000, aged 14.
Northamptonshire Police opened a murder investigation, but despite a four-year inquiry including several arrests as well as searches in Kettering, London and Wales, nobody has ever been charged.
On Monday, officers began fencing off an area in Valley Walk, Kettering, as they began a two-week operation, acting on what they said was "significant" new intelligence.
At around 11am on Tuesday, 3.5-tonne diggers broke ground in the 70m square area as the search stepped up.
Forensic archaeologists will use ground penetration radar equipment deployed to assess any movement on the section of land under investigation.
Preliminary work carried out by police has led them to believe that they will find closure for Sarah's family.