Officers hunting for missing Hull woman Joanne Nelson are searching wooded areas of North Yorkshire.
Joanne Nelson was reported missing more than one month ago
Humberside Police called in forestry experts after receiving information that Miss Nelson's body could be near western hemlock and birch trees.
On Monday, teams were combing areas of Skipworth and Holme-on-Spalding-Moor where the trees grow together.
Miss Nelson was reported missing on 14 February by her fiancÚ, Paul Dyson, 30, who has been charged with murder.
Humberside Police last week revealed that they had information that the body of the 22-year-old could be in a place where the trees are common.
A spokeswoman said: "There are a large number of wooded areas in the York area in which the trees grow and detectives would like to hear from private land owners, farmers and private growers in the York area who may have western hemlock, birch and hornbeam trees growing together."
Officers spent the weekend looking for missing clothes and other items after Miss Nelson's handbag was found near a railway line close to her home.
The force's marine investigation unit was also searching ponds at the west of Eastrington, near Howden, on Monday.