The BBC's Duncan Kirkhope: "A helicopter was used in the search"

Sally's body was found at 1215 GMT near a farm just outside the town of Perth, where she was last seen alive at a club.

Police say the body appeared to have been there for some time, and that no clothing had been disturbed. They are not treating the death as suspicious.

The area has being sealed off and a pathologist is carrying out a post mortem examination.

Sally, 18, had been missing since she left a work Christmas party near Perth on 23 December.

Police in boats had been searching the river

Police began searching fields near Perth on Sunday after reports that she had been seen walking along a lane at around 0030 GMT.

A helicopter from RAF Lossiemouth and tracker dogs were drafted in to help find the dental assistant.

Sally is understood to have left the party at the Huntingtower Hotel at about 2330 GMT on Wednesday.

A police spokesman said that a family travelling in a car on the night that Sally went missing reported having seen the teenager.