Police Scotland’s chief constable is facing calls to step aside while he is investigated over claims of misconduct.
Phil Gormley insists he “remains focused” on the job despite being the subject of a probe by the Police Investigations and Review Commissioner.
BBC Scotland understands the inquiry concerns an allegation about bullying.
Scottish Lib Dem leader Willie Rennie said it would be “necessary” for Mr Gormley to take a leave of absence to ensure an effective investigation.
Other parties have called for “full transparency” in the investigation and want the full findings to be published.
The probe follows a referral from the Scottish Police Authority, which passed the matter to Pirc for investigation.
There has been no formal indication of the nature of the complaint made against Mr Gormley, or who submitted it. However, Pirc said that “the allegations, if proved, would amount to gross misconduct” – defined as a breach of professional standards under which “dismissal may be justified”.
BBC Scotland understands the complaint was one of bullying, from a fellow Police Scotland officer.
Mr Gormley, who took up the post of chief constable in January 2016, said he was “cooperating fully with Pirc” and would provide “all necessary assistance”.
But he added: “I would like to stress that I remain focused on leading Police Scotland, ensuring that we continue to serve and protect the people of this country.”
Mr Rennie said the allegations were “incredibly serious” and needed “a thorough and prompt investigation”.
He said: “For that investigation to be conducted effectively it will be necessary for the chief constable to seek leave of absence from his post. Any leave of absence should not imply acceptance of guilt.
“Previous cases in Scotland and other parts of the UK have set a precedent, where the person who has been under investigation has temporarily stepped aside.”
There have also been calls for as much information as possible about the probe to be made public.
Scottish Conservative justice spokesman Liam Kerr said it was “essential” that there was “full transparency as to what exactly has happened”
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He said: “This will do nothing to help the reputation of Police Scotland, and the public will need to be reassured that if there has been any wrongdoing it will be swiftly dealt with.”
Scottish Labour’s Claire Baker also urged PIRC to be “as transparent as possible”, saying: “With the most senior police officer under investigation, it is vital that whatever the outcome the public maintains confidence in Police Scotland.”
Scottish Green MSP John Finnie, himself a former policeman, said it was “vital that a thorough investigation is undertaken and the full findings are published”.
The investigation is the latest in a string of controversies to hit the single police force since it was established in 2013.
Its first chief constable, Sir Stephen House, left the role in 2015 in the wake of criticism over armed officers being put on routine patrol, the force’s policies on stopping and searching juveniles and the response to a fatal crash on the M9.
Holyrood justice committee convener Margaret Mitchell, a Conservative MSP, said the police service was “rudderless”.
She said: “The chief constable is under investigation, the chair of the Scottish Police Authority is resigning. The service is rudderless.
“[Justice Secretary] Michael Matheson needs to take control of the situation. This shambolic situation can’t be allowed to go on any longer.”
A Scottish government spokeswoman said: “We note the Pirc investigation and that they will provide a report to the Scottish Police Authority.
“It would not be appropriate to comment on any current investigation.”