Police in Glasgow say Karen Buckley gave her jacket to her friend on the night she died.
Investigating officers had been trying to determine why she would have left the nightclub without it.
According to the Irish Times, the student from Cork had given her leather jacket to a friend whose zip had broken.
It comes as Ms Buckley's family return home to Mourneabbey to continue preparations for her funeral.
Alexander Pacteau (21) - from Glasgow - has been charged with her murder, and with attempting to defeat the ends of justice.
He is to make a second appearance before Glasgow Sheriff Court tomorrow.
Ms Buckley's remains were discovered last week on a farm north of Glasgow, after she vanished on a night out with friends.