The cost of compensation for survivors of childhood abuse in Scotland could total at least £200m, MSPs have heard.
A bill has been tabled which would allow victims to claim compensation beyond the current three-year time bar.
Alistair Gaw of Social Work Scotland told Holyrood's justice committee the cost could be "highly significant".
He cited an inquiry in Jersey, where the average cost of a payout was £40,000, expanding this to a possible 5,000 Scottish victims.
The Scottish government said it was "fully committed" to consultations over the issue of financial redress.
An independent Scottish Child Abuse Inquiry is currently under way, led by judge Lady Smith.
The justice committee is examining a government bill to allow victims of abuse to claim compensation beyond the current time bar, which could permit claims dating back to 1964.
Groups giving evidence to the justice committee broadly voiced support for the bill, with the Scottish Human Rights Commission saying the current time limit on claims represents a "real barrier" to justice.
However, a large portion of the debate before the committee focused on the potentially high legal costs of the change.
Mr Gaw told members: "The Isle of Jersey went down a route which didn't involve courts, and was actually an efficient and effective route of providing compensation.
"If you scale up even what happened there to the Scottish scene, you've got an average cost of around £40,000. And in Scotland that would involve around £200m, if we had the same kind of numbers, which would be around 5,000 in Scotland.
"So the scale of this, even at its potentially lowest level, is highly significant, and we have to take into account what potential impact that may have on voluntary organisations and on local authority funds, particularly in relation to issues of insurance.
"I think it's absolutely essential that we right some of these historic wrongs, and we support the measures very much. But really serious consideration needs to be given to the best way of implementing support, including the potential impact on essential services."
Police Scotland's Det Ch Sup Lesley Boal told the committee that it was "really, really difficult" to estimate what the potential cost could be.
Mr Gaw's figure of 5,000 victims matched Police Scotland's estimate that there could be 5,000 relevant files in the inquiry. However, Ms Boal stressed "that is not victims, that is files", adding: "There might be one person reporting in a file, or there might be a number."
She said the force had spent the last year going through 115,000 family protection files and other sexual crime files from the old Strathclyde policing area for the ongoing child abuse inquiry,
From this, officers identified 2,300 relevant files relating to 4,400 victims in the Strathclyde area alone - with one set of three files including 57 victims of abuse in a care setting.
Ms Boal said this was "a small proportion of children who have been abused or neglected in Scotland across the years".
She added: "Even the recent football abuse investigations that are ongoing just now, there have been 140 referrals to Police Scotland, 36 investigations raised, well over a hundred victims."
Lauren Bruce from the Convention of Scottish Local Authorities (Cosla) added that Scottish government estimates of there potentially being 2,200 victims were "conservative".
She said it was "very difficult to predict how many cases there will be", but said it could be "massive for local authorities".
Cosla has voiced "strong support" for the intent of the legislation, but said there will be "a potentially significant impact on councils, both financial and practical".
Committee convener Margaret Mitchell noted that "not everybody is going to go to litigation", saying the committee was looking at "the worst-case scenario".
Members heard that the insurance position was "unclear" for such cases, with some insurance companies potentially no longer in existence, leaving local authorities having to cover costs. Vladimir Valiente from the Society of Local Authority Lawyers said this could end with some councils having to take litigation action against insurance firms.
A government spokesman said: "The Scottish government is committed to consulting with survivor groups and other relevant parties, including Cosla, to fully explore the issue of financial redress.
"The forthcoming consultation on redress must be focused on the needs of survivors and will also involve engagement with service providers. All bodies who have liability are required in law to meet that liability."