The Stormont supremo claimed in the Assembly that legislation designed to promote openness was being used "by lazy journalists who will not do any work".

And he predicted that "reform" of the provisions will have to be introduced.

His comments have been criticised by two of the UK's leading freedom of information (FoI) experts.

Mr Paisley's outburst came just four days after an FoI disclosure to the Belfast Telegraph exposed controversial lobbying by him on the Giant's Causeway visitor centre issue.

It was discovered that the DUP leader had lambasted the Heritage Lottery Fund in 2003 for turning down a grant application by would-be centre developer Seymour Sweeney, who is a DUP member.

Mr Paisley stated in a letter that Mr Sweeney's plans had the approval of world heritage body UNESCO. That has been firmly denied by UNESCO.

The First Minister's salvo on Freedom of Information was made in the Assembly.

He said: "There is no doubt that the evidence thus far already suggests that dealing with FoI requests takes up a considerable amount of staff time.

"On occasions, the requests are of a wide-ranging and detailed nature that requires many hours of research, and are sent in by lazy journalists, who will not do any work, but who think that we should pay them and give them the information that they want.

"That, inevitably, adds time and resource pressures onto the Departments.

"If, in collating evidence on how the current procedures are working, the Departments discover that reform is needed - and I think they will - it will have to take place."

The Freedom of Information Act, which took effect in 2005, gives civil servants the right to reject requests on the grounds that they would involve excessive costs.

Mr Paisley and his Stormont Executive colleagues do not have the power to alter this legislation, as it applies to England, Wales and Northern Ireland.

To restrict its provisions, they would have to either lobby Westminster for action or table new legislation in the Assembly.

The Director of the UK-wide Campaign for Freedom of Information, Maurice Frankel, warned against any weakening of the Act.

He said it already struck a balance between cost and time issues for officials and public access to information.

"To introduce additional restrictions would really balance the whole Act against disclosure and in favour of administrative convenience and protecting politicians from scrutiny," Mr Frankel said.

"That's the last thing Northern Ireland needs. Above everything else, it needs openness and higher standards of scrutiny to demonstrate that the political system is functioning in an open and accountable way and is doing the job that people expect of it.

"For it to go in the opposite direction would undermine public confidence in what politicians were doing - at a time when they most need public confidence."

Leading FoI campaigner Heather Brooke, who has written an acclaimed book on the subject, said: "Let's be clear, we are talking about information created and maintained at public expense in the name of the public.

"In a democracy, it shouldn't be too much to ask that the public be able to access the fruits of their labour. Politicians aren't some special elite who get to fund their own secret libraries at taxpayers' expense.

"Public servants can refuse requests that are too broad already. If they want less work for themselves there is a simple solution - publish all the information they've released proactively and speak to requesters directly to help narrow down excessive requests."

The Stormont First Minister issued a glowing press release on Government FoI disclosures in July, in which he stated: "In response to requests concerning a wide range of issues of public interest, our departments have disclosed significant amounts of information never released previously.

"They are making considerable strides towards achieving our goal of more open government."