Britain’s Guardian Media Group has been rapped on the knuckles by media regulator, Ofcom, for broadcasting a generic promotion for digital radio, claiming the output had ‘CD quality sound’.

GMG owned station, 102.2 Jazz FM, says the ad was broadcast in good faith, as part of a wider campaign to promote the growing use of DAB digital radios.

However, listeners complained that the boast of CD quality was unproven, as most radio stations broadcast at a slightly inferior technological level than compact discs.

Ofcom has ordered GMG not to allow the ad to be broadcast again without an amendment on the claims.