The information gained in a privately funded search for missing teenager Aleksandr Benga from Stornoway will be passed to police.
A team from the UK charity Specialist Search Dogs searched in and around the town for three days, from Friday to Sunday.
While they did not find Aleksandr, they say they have narrowed the area in which they will look for the teenager during a future search.
Sixteen-year-old Aleksandr was last seen on the grounds of Lews Castle in Stornoway on November 18.
Despite searches by police, specialist divers, the coastguard helicopter, and teams, together with volunteers, he has not been seen since.
Search team worked for three days but did not find Aleksandr Benga
The Specialist Search Dogs team plans to return to the Isle of Lewis in the “very near future” to resume the search.
In an update, the Search for Aleksandr Benga Facebook page organiser, Doreen Culley, said: “They have worked solidly for three days, starting at first light and only stopping when the light was gone.
“Sadly, on this occasion, we were unsuccessful in bringing Aleksandr home to Viktoria (his mother).
“But the team’s findings have ruled out many hypotheses, theories, and gossip about where Aleksandr is.
“Being able to rule out many acres and analyzing dog reactions and search team observations of the environment enables the likely location of Aleksandr to be narrowed further.
“Our main focus has always been to allow Viktoria to control what we do and how we do it, and with this in mind, the team met with her today (Sunday) and will be returning to the island to continue the search in the very near future.
“A comprehensive report of the search will be completed this week and made available to the police and island search and rescue.
“The search for Aleksandr is not over. It continues.”
A GoFundMe page to pay for the search has so far raised more than £8,700.
Aleksandr is described as 6ft 2in tall and of slim build, with short brown hair.
When last seen, he was wearing a beige jumper and black jeans.
He may also have a red jacket and a yellow beanie hat.
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