A senior Police Scotland officer suspended from duty last year is now the subject of a formal misconduct investigation.
Assistant Chief Constable Bernard Higgins was suspended in November by the Scottish Police Authority (SPA) after ''a number of criminal and misconduct allegations''.
Three other officers were also suspended and a further two placed on restricted duties, with the Police Investigations & Review Commissioner (Pirc) directed to investigate the allegations.
The watchdog has now confirmed that Mr Higgins - who has denied any wrongdoing - is subject to a second investigation into misconduct.
He was served with a Notice of Investigation on Thursday.
A Pirc statement said: "The Commissioner assessed the various allegations and considers that some, if proved, would amount to gross misconduct and others, if proved, would amount to misconduct.
"The senior police officer was served with a Notice of Investigation on January 4 2018 and informed that he is the subject of a misconduct investigation.
"Once the investigations are concluded, the Commissioner will submit a report about the criminal allegations to the COPFS and another in relation to the misconduct to the SPA.
"In the report provided to the SPA, there will be a summary of evidence and an opinion on whether the misconduct allegations should be referred to a misconduct hearing."
Pirc is already investigating separate allegations of gross misconduct against Scotland's top police officer, Chief Constable Phil Gormley.