Police Scotland might need to bring in senior officers from other UK forces to deal with the "vacuum of leadership" following the chief constable's decision to step aside while allegations of gross misconduct are investigated, the Liberal Democrats have said.

Justice Secretary Michael Matheson will address Holyrood on the single force this week following a request from the Lib Dems for a parliamentary statement.

The party wants the government to consider bringing in additional leadership and resources, and will call for Mr Matheson to address concerns about how the force is being led.

Scottish Liberal Democrat leader Willie Rennie said: "The statement is the opportunity for the government to set out how it plans to deal with the latest crisis in Police Scotland since centralisation.

"There is no chairman or chief executive of the Scottish Police Authority and now we have no chief constable. There is a vacuum of leadership in the whole organisation. That is why we need the Scottish Government to address the situation and consider whether additional resources and leadership is required.

"It might be necessary to draft in senior officers from other forces in the United Kingdom."

Police Scotland's chief constable Phil Gormley announced on Friday he is temporarily stepping aside as two allegations against him of gross misconduct - one from a senior officer on the force executive - are investigated.

He denies the accusations, which could lead to his dismissal if proven, and has taken "special leave".

Deputy Chief Constable Iain Livingstone has taken over leadership in Mr Gormley's absence.

Chairman of the force oversight body the Scottish Police Authority (SPA) Andrew Flanagan announced his resignation in June facing criticism over transparency and governance at the authority remains in post until his successor is appointed.

Last month SPA announced its chief executive John Foley is to take early retirement as it set out structural changes which will make his role redundant.

Mr Foley had faced calls to resign after an Her Majesty's Inspectorate of Constabulary in Scotland inspection found ''shortcomings'' in his capacity to provide expert advice and support to the SPA board.

A Scottish Government spokesman said: "The Cabinet Secretary for Justice will address MSPs in a parliamentary statement later this week.

"Deputy Chief Constable Iain Livingstone will lead Police Scotland through this period of absence, and he is well equipped to deliver the leadership required.

"It would be inappropriate for ministers to make any more detailed comment at this stage while an independent investigation is taking place."