The single force launched an investigation last October after it was given a report of a serious sexual offence at the Scottish Police College at Tulliallan.

A 36-year-old officer was suspended and a probe continues but no case will be submitted to the procurator fiscal.

A Police Scotland spokesperson said: “An investigation was carried out by specialist officers and a report outlining enquiries undertaken and seeking advice was sent to the Procurator Fiscal.

“Following guidance from the Crown Office and Procurator Fiscal Service (COPFS), the criminal investigation into this complaint has now concluded and a case will not be submitted to the Procurator Fiscal at this time.

“A 36-year-old officer remains suspended from duty and a misconduct investigation is ongoing.”