UPDATE: Phones in other child murder cases are now suspected to have been hacked.

ORIGINAL: Many observers have been wondering when exactly the phone hacking scandal currently engulfing Rupert Murdoch's British newspapers would cross over into the public consciousness.

Sure, the scale of the phone hacking was ridiculous, but most of the victims were either celebrities (who thus don't deserve their privacy) or obscure officials that the public found it difficult to relate to.

Now, it appears the tipping point may have been found.

Murdoch's paper The News of the World has been accused of hacking into the voicemail of Milly Dowler, a 13-year-old schoolgirl who went missing in 2002. It was discovered later that she was sexually assaulted then murdered.

Allegedly, after the tabloid hacked into Milly's voicemail, they then went onto delete messages when the mailbox became full. Not only did they destroy evidence, including messages left in the time surrounding Milly's disappearance, but when friends and relatives realized the mailbox was no longer full, they thought the schoolgirl may still be alive.

The Guardian writes:

The Dowler family then granted an exclusive interview to the News of the World in which they talked about their hope, quite unaware that it had been falsely kindled by the newspaper's own intervention. Sally Dowler told the paper: "If Milly walked through the door, I don't think we'd be able to speak. We'd just weep tears of joy and give her a great big hug."

Here's why this matters for Murdoch:

The Milly Dowler murder trial only recently finished, and may be one of the most prominent murder trials in the last 10 years in the UK. The Dowler family are hugely sympathetic victims.

All the major British broadsheet papers, even The Times of London (owned by Murdoch), ran with the story on their front page. Prime Minister David Cameron has said that if true, the hacking was a "truly dreadful act." Cameron has now called for a police inquiry into the hacking.

Rebekah Brooks, Murdoch's right-hand lady, was editor of the News of the World at the time. This is the first time Brooks has been implicated in any phone-hacking cases. Brooks is Chief Executive of News International, News Corp's British wing.

Murdoch is in the middle of the takeover of British satellite TV monopoly BSkyB, a move already fraught with controversy. Attempts are now underway to halt the takeover.

Could this finally the tipping point? It certainly seems that the Murdoch clan are taking this more seriously then ever before. They are now promising a full investigation and Brook's has sent an email denying she was involved.

Amazingly, some News International executives have apparently told the BBC's Robert Peston that there may be even more shocking examples of phone hacking out there.