The cost of replacing a police computer network, described as "like something from the Beano", is estimated to be £45 million over a decade, the First Minister has announced.

Police Scotland's Chief Constable Stephen House may also be handed control over human resources and other responsibilities, bringing an end to a prolonged power struggle between the force's civilian and operational arms, according to a Labour MSP.

The Scottish Government estimated that integrating the computers of the old eight forces would initially cost £12 million over three years, but this has since been branded a significant underestimate.

Police have been privately briefing for over two years that integration would cost around £45 million, according to the Scottish Police Authority (SPA), but this figure has only now emerged publicly at First Minister's Questions.

Information and communications technology (ICT) integration has been described as the police's number one priority amid complaints that they have less computer support than a washing machine repair man.

Holyrood scrutiny of ICT has been relegated to second billing, following the resignation of three senior SPA executives.

First Minister Alex Salmond told MSPs that the resignations "will have no impact" on ICT integration because SPA's chief information officer is still in post.

"The i6 proposal for the acquisition of the single ICT system to cover recording, management, analysis of data and crime, vulnerable persons, criminal justice and custody, missing persons and property is a major advance," he said.

"I'm pleased to say that discussions with the SPA indicate the estimated total cost of £45 million over 10 years is affordable within their existing budget."

Labour MSP Graeme Pearson, a member of Holyrood's Justice Committee, said: "This is the first time this number has been brought to light and brings to a conclusion the ambiguity that has existed up to now about the cost and the likely way forward for the service; £12 million was the Government's guess and it was obviously an unreasonable figure.

"I also understand that at long-last officials have come together and many of the major governance issues have now been reallocated so that Police Scotland will be in charge of human resources, finance and corporate services etc.

"The SPA will do what it was designed to do: utilise governance and accountability by watching the way the service delivers according to the strategy.

"Up until now the SPA deemed that it would be responsible for all of the support staff, all the ICT, be the accountable officers for finance and HR and so forth. There is a letter going out after today that will set out the new arrangement."

An SPA spokesman said the papers for the next SPA meeting on June 26 will be published tomorrow and will include the revised ICT strategy.

"There has been an awareness of a number of that ilk (£45m) for two or more years around i6. It is certainly talked about very openly in the sessions that we have had so far," he said.

"In some ways, the £12 million was a theoretical figure that existed only in a government document. There is no ringfenced sum of money in our capital budget purely for technology."

Holyrood's Justice Sub-Committee on Policing will quiz SPA chairman Vic Emery and Mr House on the SPA resignations on June 27, with ICT relegated to second billing.

Speaking at previous committee meetings, Mr Pearson has described the police IT network as "like something from the Beano" and complained that "the guy that fits my washing machine has better IT support".

The committee has heard that the current "hamfisted" IT network is like working with "chalk and slate", still relies on outdated floppy discs, does not comply with police regulations and could leave police open to criticism if a prisoner dies in custody.

A Scottish Government spokeswoman said: "The costs referred to are the i6 programme which is for a single, national ICT solution for Police Scotland. This will cover the recording, management and analysis of data on crime, vulnerable persons, criminal justice, custody, missing persons and property.

"The estimated total cost of i6 is £45.48 million over 10 years, 2013-14 to 2022-23. Discussions with SPA indicate that this is affordable within their existing budget.

"It is estimated that the new system could achieve cash savings of £60 million over 10 years, plus savings in police staff and officers' time.

"The SPA board aim to decide on the programme at their meeting on 26 June."