DNA found on the coat of a teenage girl killed in 1977 matched that of the man accused of her murder, a court has heard.

The High Court in Livingston was told the chances of it coming from another man unrelated to the accused, Angus Sinclair, was around one in a billion.

A forensic scientist reached the conclusion after analysing staining on Helen Scott's coat, jurors heard.

Sinclair, 69, denies raping and murdering Helen and her friend Christine Eadie, both 17.

The pair were last seen at Edinburgh's World's End pub on October 15 1977.

Christine's body was found the following afternoon at Gosford Bay, in Aberlady, East Lothian, while Helen's body was discovered a few hours later in a wheat field near Haddington, East Lothian.

The ninth day of the trial heard evidence from forensic scientist Martin Fairley, 52.

Sinclair denies the charges against him and has submitted three special defences of incrimination.