No one has been traced for the alleged theft of a top-secret dossier from police HQ in Dundee, and police have now closed the inquiry.
The document was allegedly stolen in May from a secure unit in the Tayside Division headquarters in Dundee’s Bell Street.
It is understood the document was put together last year by Angela Wilson, former deputy chief constable of Tayside Police.
It outlined a series of allegations of unprofessional behaviour made against former chief constable Justine Curran.
A police spokesman said: “The inquiry is closed. No individual has been identified as being responsible and no one has been arrested or charged.”
A major inquiry team was sent to Dundee from Strathclyde to investigate the incident. The document was allegedly stolen from an area that was kept locked at all times.
It was understood the dossier included information relating to the former chief constable’s conduct regarding a text message she sent to her personal assistant, Theresa Noble.
Although she admitted behaving unprofessionally, Ms Curran received the full backing of Tayside Police Joint Board.
Ms Noble and her former partner Paul Martin were arrested a few weeks later in connection with alleged insurance fraud and wasting police time.
Charges were dropped against Ms Noble when she agreed to act as witness against Martin, who was later found not guilty of both charges.