The Belfast Telegraph reports that in a radio ad for AV Browne, they claimed themselves to be "Northern Ireland's most effective advertising agency". Rivalry agency LyleBailie International made a complaint to the ASA.
AV Browne defended its radio claim, pointing to effectiveness awards it had received from the Institute of Practitioners in Advertising (IPA).
LyleBailie retorted, highlighting its awards tally from a number of bodies, including the IPA and the Institute of Advertising Practitioners in Ireland.
In a ruling issued today, the ASA stated that the basis for AV Browne's "most effective" claim should have been included in the radio advert.
While recognising that the IPA awards are well-respected in the industry, the authority said: "Because effectiveness could be measured in a number of different ways and the ad did not make clear the basis on which AV Browne were claiming to be the most effective, we considered the ad was misleading," it stated.
David Lyle, chief executive of LyleBailie has called for an apology from not only AV Browne but also the radio station, U105, which aired the spot.