Police Scotland needs an additional £50 million to avoid axing 750 police officers, MSPs have been warned.
The public spending watchdog said the cash would be needed over the next two years as the force struggles to balance its books.
It prompted political opponents to accuse the Scottish Government of running Police Scotland "into the ground."
The force has been faced with similar funding black holes in recent years and has had to rely on Government bailouts in the form of "cash allocations" to see it through.
The reduction of 750 officers was set out by police chiefs in August as one way to break even, but this would see the size of the force to shrink less then 16,500 down from 17,300 at the moment.
Stephen Boyle of Audit Scotland told Holyrood's Justice committee that a major cash injection over the next next two years is needed to avoid this.
"Essentially it will be tens of millions of pounds - I would assume in the region of £40-50 million that it would require," he said.
An Audit Scotland report to the committee outlined that the Scottish Police Authority needs a long term cash injection of £298 million over the next nine years in order to have sufficient information technology to support essential policing going forward.
These funding issues have been raised while Police Scotland is having to deal with rising sexual crime, crimes of fraud and a 10 percent rise in violent crime over the last year alone.
Tory justice spokesman Liam Kerr said: “This massive funding black hole shows the SNP is running Police Scotland into the ground.
“Our police officers have been saying that they do not have sufficient funding for some time, but the SNP continues to sit on their hands.
“Under the SNP we have seen significant increases in sexual crime, violent crime and crimes of fraud which all heap increased pressure on our police service.
“The SNP cannot expect Police Scotland to function properly without enough cash so this could jeopardise public safety.
“Under the SNP our prisons are overcrowded, courts are overflowing and now police numbers could be cut by 750 – that’s a disgraceful record.”