GCap, the commercial radio group behind Capital 95.8 and Classic FM, has been fined a record £1.1 million by Ofcom, the media regulator, for manipulating phone-in quizzes to stop prizes from being won too quickly.

Ofcom has fined 30 local radio stations across GCap's One Network of stations in the highest financial penalty imposed to date for the broadcast of radio content. The fine works out at £37,000 per station.

GCap was recently acquired by Global Radio, chaired by the former ITV chief Charles Allen, and the fine will add to Global's worries, because it will severely dent profits at GCap at a time when it is facing numerous challenges, such as increasing pressure on radio advertising revenues, competition in the London market and the strength of the BBC. Interim pre-tax profits at GCap fell to £5.6 million.

An investigation found that, on a number of occasions, programme makers deliberately put entrants, who sent incorrect text messages, on air to prevent the prize from being won too quickly. The competition, which took place between January 15 and February 8 last year, airing between 9am and 3pm each weekday, was called Secret Sound.

Ofcom launched an investigation after a complaint made to PhonepayPlus, the premium rate phone line regulator, by a whistleblower. It is understood that the misconduct had been agreed in advance at a programme team meeting by a director, who Ofcom said was a “mid-ranking employee”. Ofcom said: “As a result, those listeners who had paid to enter the competition on these occasions had no chance of winning.”

GCap said it took the ruling “extremely seriously”. “The new management and owners look forward to building a strong future for the commercial radio industry where the trust of its listeners and regulator is of the highest importance,” it said, adding that measures were being put in place “to build on the already improved controls”.

Ofcom has also directed each of the 30 licensees to broadcast a summary of Ofcom's finding on two separate occasions.

The One Network competition breached two Ofcom rules. The first states that competitions should be conducted fairly, prizes should be described accurately and rules should be clear and appropriately made known. Secondly, Ofcom states that any use of premium rate numbers must comply with the code of practice issued by PhonepayPlus.

Networked shows and competitions are becoming more commonplace as a means of cutting costs but still providing quality programming. However, with the GCap fine calculated on a per station basis, radio executives and programmers planning networked shows will have to tread carefully in future.

Ofcom's penalty follows its recent record £5.6million television fine to ITV for abusing premium rate phone services in viewer competitions.

Separately, the media regulator is looking into a Capital Radio competition that had to be reopened after the £155,000 winner was found to be ineligible. The London station said that it recently brought the “London iTest” competition to the regulator's attention and does not believe that it is in breach of any codes.

One Network stations include GWR in Bristol and Swindon, Mercury FM in Crawley, Plymouth Sound, Coast 96.3 and Chiltern FM in Bedford and Dunstable.

“This was a particularly serious case where the broadcaster had deliberately deceived its audience, with the result that the revenue from this premium rate competition was likely to have been greater than it otherwise would have been,” Ofcom wrote in its report.

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