The Charity Commission for Northern Ireland has rejected nearly half of the requests processed this year under the Freedom of Information Act, saying it is concerned they are "vexatious".
In the year to 5 April 2013, the CCNI received a total of 10 requests, but in the nine weeks since the start of the new financial year it has received 18, five of which are being processed, a spokeswoman for the commission said.
Of the 13 that have been concluded, six have been rejected. Two of those six were deemed to be vexatious by the commission, partly because of a "high volume and frequency of overlapping communications and correspondence from the applicants", the spokeswoman said.
The other four rejected requests were made under what the CCNI believed were pseudonyms and were seen as potentially vexatious.
"Having fully considered the nature, similarity and timing of the four requests, the commission was concerned that the requests might have been vexatious and had been submitted under pseudonyms," the spokeswoman said. The applicants had since been asked to provide their identity, but none had yet done so, she said.
Ten of the 18 requests this year have been made through the website WhatDoTheyKnow.com, which publishes all correspondence between the individuals making these requests and the CCNI.
Two of these, currently awaiting review, were made by Greg Burke. Burke was one of five people whose membership of the charity Lough Neagh Rescue was revoked by the CCNI before being reinstated by the charity tribunal on appeal.
Robert Orton, another of those Lough Neagh Rescue members, has had a freedom of information request turned down. Burke said he had not made any requests under pseudonyms, and he was not aware that any other of the five had done so.
According to the frequently asked questions section of WhatDoTheyKnow.com, applicants must use their real names for a freedom of information request to be valid, although public authorities receiving the requests should still consider requests made under pseudonyms, it says, according to a good practice guide from the Information Commissioner's Office.
The spokeswoman for the commission said that the organisation took its freedom of information responsibilities "extremely seriously and, as such, believes it is acting in accordance with the legislation".