A senior officer from Police Scotland has been suspended amid an investigation into criminal conduct.

Assistant Chief Constable Bernard Higgins was suspended with immediate effect by the Scottish Police Authority (SPA) on Friday afternoon.

Three other officers have also been suspended and two have been placed on restricted duties.

A spokesman for ACC Higgins said he "denies and rejects" any allegations of wrongdoing.

The independent police watchdog is investigating allegations of criminal conduct and gross misconduct.

In a statement, Deputy Chief Constable Iain Livingstone confirmed the suspension of ACC Higgins, who was responsible for operational support, custody and criminal justice.

He said: "I can confirm that Assistant Chief Constable Bernard Higgins was suspended today by the Scottish Police Authority.

"In addition, three other officers have been suspended, and two others placed on restricted duties, by Deputy Chief Constable Rose Fitzpatrick.

"This is in connection with an investigation by the Police Investigations and Review Commissioner (Pirc).

"At this time our focus must remain on continuing to meet the operational challenges that we face each day."

Anonymous allegations

He added that Assistant Chief Constable Nelson Telfer would take responsibility for the operational support portfolio.

However a spokesman for ACC Higgins said he denied wrongdoing.

"He will fully cooperate with the investigation. He intends to resume his duties as soon as this matter has been resolved," he added.

BBC Scotland understands the allegations are connected to a wider criminal investigation.

They are not connected to the separate Pirc investigations into allegations of misconduct against Chief Constable Phil Gormley who is currently on "special leave."

Nor are they connected to inquiries into allegations that officers in the former counter-corruption unit abused their position when attempting to find the source of a journalist's information.

Who is Bernard Higgins?

ACC Higgins joined Strathclyde Police in 1988 and served in uniform posts across Glasgow and Lanarkshire.

He became a superintendent in 2006 and was then promoted to detective chief superintendent and head of the public protection unit in 2010.

Later in 2010, he was made divisional commander in charge of Glasgow Central and West Division.

He was appointed Strathclyde Police Temporary Assistant Chief Constable (Territorial Policing) in March 2012.

In January 2013, he became assistant chief constable of Police Scotland with responsibility for operational support before assuming responsibility for the wider justice and support portfolio.

In his current role, which he was appointed to in September last year, he has responsibility for the operational support, custody and criminal justice divisions.

The decision to suspend Mr Higgins was taken by the SPA board after it was alerted to the criminal and misconduct allegations by the Pirc.

In a statement, the SPA said the suspension would be reviewed in four weeks or if there is a change in circumstances.

The Pirc said it initially referred the anonymous allegations to the Crown Office and Procurator Fiscal Service, as it is responsible for the prosecution of crime.

Misconduct investigation

The Crown Office decided an independent investigation should be carried out by the Pirc and that is now under way.

As the complaint also included allegations of misconduct by a senior police officer, the commissioner referred the matters to the SPA on 18 October.

The SPA suspended Mr Higgins on Friday and referred allegations of gross misconduct to the Pirc

The commissioner is now carrying out an assessment to establish whether a misconduct investigation is required.

'Get a grip'

A spokesman for the commissioner said: "Following receipt of anonymous allegations of criminality by officers, including a senior officer, serving with Police Scotland, the Commissioner referred the allegations to the Crown Office and Procurator Fiscal Service (COPFS).

"This was to allow the COPFS to consider whether the criminal allegations should be investigated by the Commissioner.

"The COPFS decided that an independent investigation should be carried out by the PIRC and this is now under way."

The Scottish government has issued a statement saying that as the matter was under investigation by the Police Investigations and Review Commissioner it was unable to comment further.

However, Liam Kerr, the justice spokesman for the Conservative Party, called for Scotland's justice secretary to come "out of the shadows" on the difficulties faced by Police Scotland.

He told BBC Radio Scotland: "The conspicuous absences of the justice secretary - my view would be that he's got to step out of the shadows and get a grip on this because it keeps happening on his watch."