Prince William first suspected that mobile phones used by the Royal household were being tapped after the News of the World published a seemingly innocuous story about his knee.
Prince William became suspicious of a News of the World story
The brief piece, which did not cause the kind of sensation some royal stories have in the past, appeared in the paper's Blackadder column.
It said: "William pulled a tendon in his knee after last week's kids' kickabout with Premiership club Charlton Athletic.
"Now medics have put him on the sick list."
The article went on to claim: "He has seen Prince Charles's personal doc and is now having physiotherapy at Cirencester hospital, near his country home Highgrove."
What caused consternation was that so few people had been aware of the doctor's appointment in the first place.
Both the prince's parents have been victim of similar phone-tapping scandals, where intimate conversations soon became headlines across the world.
Moreover, newspapers can still add masses to their circulations with a major royal exclusive.
The prince's concerns grew a week later when the same tabloid printed a story about how he borrowed broadcasting equipment.
This time the story said: "If ITN do a stock take on their portable editing suites this week,
they might notice they're one down.
"That's because their pin-up political editor Tom Bradby has lent it to close pal Prince William so he can edit together all his gap year videos and DVDs into one very posh home movie."
Recalling the prince's concern, Mr Bradby said: "When he and I hooked up we both looked at each other and said 'Now, how on earth did that get out?'."
"We worked out that only he and I and two people incredibly close to him had
actually known about it."
He added: "His chief of staff is a former SAS officer and his attitude was 'if this
potentially (is) happening to us, then who on earth else could this be happening
Meanwhile, 14 other "alternative" charges which both Goodman and Mulcaire originally faced were ordered to be left on the file.
They alleged that both men had intercepted "intentionally and without lawful
authority" voicemail messages left for a number of other high-profile names.
These were the Prince of Wales's aide, Helen Asprey; Jamie Lowther-Pinkerton,
the ex-SAS officer who is private secretary to Princes William and Harry; and
Prince Charles's communications secretary, Paddy Harveson.
Other victims of Mulcaire's hacking were Sol Campbell's agent Sky Andrew, chairman of the Professional Footballers Association Gordon Taylor, MP Simon Hughes and the international supermodel Elle Macpherson.
He intercepted voicemail messages left for each of them.