Parents are upset the cult TV amphibian, known for its annoying "ding ding dididing" ringtone, is displaying more than it should between its legs with a penis clearly visible.
The Advertising Standards Authority has had 60 complaints about the offending body part, which parents say should not be there, because "frogs don't have a penis".
The ringtone has made around £10m for the internet firm thanks to its Swedish creator David Malmedahi, a 24-year-old computer components salesman from Gothenburg, and Erik Wernquist who designed the frog.
It was Daniel, who as a 17-year-old in 1997, sat down at his computer and recorded himself imitating his friends' mopeds, unaware that his recording would one day become the Crazy Frog and the most successful ringtone in the world, the company claims.
Ads for the mobile phone ringtone have played hundreds of times on TV channels and radio stations over the last few weeks. Now a dance mix has been recorded and played on Chris Moyles' Radio 1 breakfast show.
Jamster has said it now promises to censor the frog even though the BACC cleared it with a certain rating and has assured parents the altered ad is already being screened.
Robert Swift, UK marketing manager for Jamster, said: "We didn't expect people to be offended at all. It didn't even enter our heads that there might be a problem and it certainly wasn't intentional."
Jamster is part of the VeriSign family, a leading wireless content mediation company. The company develops, markets and distributes digital content and applications for the newest generation of GPRS, MMS and 3G mobile handsets.
The ASA will be publishing the findings of its investigation shortly.
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