Police Scotland support staff are facing further redundancies next year as the force attempts to balance its books in 2015/16, Chief Constable Sir Stephen House has told MSPs.

The organisation has an overall strategic target of saving £1.1 billion by 2026, Holyrood's Justice Committee heard.

"We are internally very confident that we will meet that strategic target," Sir Stephen said.

He warned that the path ahead is "not smooth" and there is no area - except police officers numbers, which are protected - which will not be considered in order to make savings.

Police Scotland is already on course to balance its budget for 2014/15, with savings in the region of £60 million. A similar level of savings is also required for 2015/16.

"We have said we are anticipating some real challenges next year in the budget to balance it," Sir Stephen said.

"We have identified what we saved last year, what we are on course to save this year and what we expect the gap to be next year, and it is all around the mid-60s basically."

About 2,000 civilian staff have been cut through voluntary redundancies and early retirement schemes since 2009.

Sir Stephen said further cuts in this area were likely but there was "no specific target" on numbers.

There are already plans to reduce the number of police control rooms.

"Inevitably there will be more voluntary redundancies, early retirements in that area, because the staff know what our plans are going forward with control rooms," Sir Stephen said.

There are also plans to review custody centres.

"That may result in the reduction of some civilian staff and we will continue to look at all the other functions we carry out such as finance, HR and ICT to see if we can be more efficient with our budget," he added.

"That might mean offering more redundancies to more civilian staff, so, yes, I anticipate there will be more reductions in civilian staff."

Savings could also be made by reducing the force's property portfolio, improving the energy efficiency of buildings and the vehicle fleet, Sir Stephen told MSPs.

Reviews of IT and communications systems, the procurement of contracts, overtime for police officers and the number of senior ranked officers would also be looked at.

"There is no area that we won't consider looking at to balance the budget," Sir Stephen added.

New Justice Secretary Michael Matheson, giving evidence to the committee for the first time, said the Scottish Government was committed to its pledge to maintain policing levels of 17,234.

He said: "We remain committed to the 1,000 extra officers from our 2007 commitment and I would expect both Police Scotland and the SPA to operate within that commitment."

Mr Matheson denied a suggestion from MSP John Finnie that the commitment was "overt political interference" in policing that had "knock-on consequences" for other staff.

"There must come a point when the equation doesn't match up," Mr Finnie said.

Mr Matheson responded: "It's a matter for Police Scotland to determine how they configure their staffing levels.

"There was always an anticipated level of overlap with the merger of eight forces in terms of back-room functions that may have been undertaken by staff side. Clearly that has to be addressed.

"We also have a policy of no compulsory redundancy, where staff are able to get redeployed or to go onto work in a different field or to take a voluntary severance package if they choose to as well.

"I'm always prepared to discuss with staff-side some of the challenges which they face amongst their staff, and I recognise some of the challenges which they face, but as a Government we also have a clear commitment which we remain committed to in terms of numbers of policing and we will continue to pursue that policy."

The new justice secretary said he intended to continue to press the UK Treasury on its decision not to allow Police Scotland to recover VAT.

He said: "To date, the Treasury ministers have refused to change their policy position on this matter, which we think is unacceptable.

"We are in a situation where this is costing the Scottish police service some £24 million per year.

"If we were in a position where we could secure the exemption in the same way that other forces in the UK have been able to do so, that's money that clearly could be invested."

Committee convener Christine Grahame MSP said members had been told that would equate to 680 police officers.

Mr Matheson added: "I certainly intend to pursue this issue with vigour. I'm very clear that the present situation is completely unacceptable."

MSPs quizzed Mr Matheson on the pressures facing Scotland's court system and staff.

He responded: "We are under tremendous pressure as the Crown Office and the justice system is no different from the rest of our public services.

"The UK Government is cutting the Scottish Government's budget and we have to recognise that in how we manage our services. That's why reform is so important."

Margaret Mitchell MSP pressed him on the "negative impact" of court closures on the number of cases being dealt with in the 26-week target time.

She called for the remaining four courts due to close by January 2015 to be looked at again "to see if this is a realistic prospect".

Mr Matheson said the court closure programme represented only 5% of total court work.

He said: "The Scottish Court Service are very clear from the discussion I've had with them that any delays that may have been experienced anywhere in the system have not come about as a result of any court closures and that they're very confident that the existing court estate which they have is sufficient to meet the demand and the predicted demand going forward within the court service in Scotland."

Speaking after the committee, Sir Stephen warned that the VAT bill will have a significant impact on his resources when it moves from the Scottish Government to the Police Scotland budget.

"The VAT bill for Police Scotland is £23 million a year, that comes out of the public purse," he said.

"We're the only police force in the UK that I am aware of that pays VAT.

"Now there's 43 police forces in England that don't pay VAT. The Police Service of Northern Ireland obviously is a unified police force but they don't pay VAT.

"The National Crime Agency, which covers the whole of England and Wales and has a footprint in Scotland as well, don't pay VAT but Police Scotland does.

"That is £23 million that we could spend on other things - it is the equivalent of 680 officers.

"At the moment the (Scottish) Government is covering the cost, but in a couple of years time that will be coming out of the police budget and that will be significant.

"If we have to find the money for VAT rather than the Government it will have an impact on our budget, there is no doubt about it."