The suspension of an Assistant Chief Constable and three other police officers is "unwarranted", the Scottish Police Federation (SPF) has said.

ACC Bernard Higgins was suspended as part of an investigation into "criminal and misconduct allegations."

The investigation is being carried out by the Police Investigation and Review Commisioner (PIRC).

ACC Higgins, who has responsibility for Operational Support, Custody and Criminal Justice divisions, has denied any wrongdoing.

The SPF, which represents two of those who were suspended, said it believed the action was unwarranted.

A spokesman said: "It is important to remember that this involves a handful of officers in a service of over 17,000.

"Whilst it is always difficult to talk about specifics due to an ongoing investigation the information we have suggests the suspension of our members and others is unwarranted.

"Our members rightly ask what it is that allows some to be granted leave while under investigation but for that same opportunity not to be extended to them."

ACC Higgins joined Strathclyde Police in in 1988 and would be eligible for retirement next year after completing 30 years' service.

In Police Scotland, he had responsibility for the operational support, custody and criminal justice divisions.

A PIRC spokesman 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 underway."

The suspensions come just two months after Chief Constable Phil Gormley, who has been the subject of five complaints, was placed on "leave of absence".

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

"He will fully cooperate with the investigation.

"He intends to resume his duties as soon as this matter has been resolved."