As reported by Ofcom in April, E! Entertainment broadcast consecutive episodes of the racy show at various times during the day on December 27, 2011. One was shown as early as 10am.
The content of these episodes included material that was deemed "unsuitable for pre-watershed broadcast", and the situation was compounded as it occurred during the Christmas period when children were more likely to be watching.
Girls of the Playboy Mansion follows the lives of Hugh Hefner's girlfriends who live with him at the Playboy Mansion.
The offending episodes aired by E! last December featured prolonged sequences of nudity - albeit with breasts, buttocks and genitals blurred - as the cast searched for the 55th Playmate glamour model.
Models were filmed as they posed and photographed during casting sessions for Playboy magazine. There was also a sequence involving a lingerie party at the Playboy Mansion, featuring numerous scantily clad Playboy glamour models, and shots of a male stripper in a thong "thrusting his buttocks in the face of the mother of one of Mr Hefner's girlfriends".
E! had previously been found guilty of similar breaches involving two other programmes - 50 Super Epic TV Moments and Keeping Up With the Kardashians - that were wrongly shown before the 9pm watershed.
The cumulative effect of these "serious and repeated" breaches prompted Ofcom to impose the £40,000 financial sanction on E!, payable to the HM Paymaster General.
E! Entertainment must also broadcast a statement of Ofcom's findings, on a date and in a form to be determined by Ofcom.
The broadcaster had said that Girls of the Playboy Mansion was aired at an unsuitable time because its LA-based compliance team had marked the show as "suitable for daytime scheduling".
Ofcom asked why the name alone had not triggered concerns among the London-based senior managers, but they said that they did not have any reason at the time to doubt the decision taken in America.
E! Entertainment has promised to improve its compliance procedures and Ofcom has decided not to revoke its broadcasting licence over the serious breaches.
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