Thames Valley Police say a rucksack and other items have been found at a house in Milton Keynes.
Police have begun a murder probe following the disappearance of 19-year-old Leah Croucher.
Thames Valley Police said they found Ms Croucher’s “rucksack and personal possessions” at a property in Loxbeare Drive in Furzton, Milton Keynes.
The teenager was last seen on CCTV in the city on 15 February 2019.
Officers have been at the property since 18:30 BST on Monday after they received information from a member of the public.
Police described the scene as “challenging and complex” and said they would be there for “a significant period of time”.
Det Ch Supt Ian Hunter said: “Following a call to police on Monday, we attended an address and located items of concern within the property.
“Leah’s family have been kept updated and continue to be supported by officers, and we are urging the public and media to think of her family and not to speculate further while this investigation is in the early stages,” he said.
Since Ms Croucher’s disappearance three years ago police have carried out more than 4,000 house-to-house inquiries and reviewed 1,200 hours of CCTV footage.