TV executive Alan Yentob (pictured, Reuters) has told the High Court that he felt "invaded and sickened" by the phone-hacking to which he was subjected by journalists from Mirror Group Newspapers.
The BBC's creative director said he had been profoundly shocked by the true extent and intensity of the intrusion into his private life.
"I am now acutely aware that I, along with my family, friends and associates, have been violated on a truly massive scale. I can only describe the feeling as a violation. It did not happen just once," he said.
"It feels as if someone has been able to go in and out of my home, the most private of places, and search through my personal belongings day in, day out, helping themselves to whatever they think might be worth something. It has left me feeling invaded and sickened.
"It is extremely disturbing to think that these people knew about so many aspects of my personal and professional life and my most private of conversations.
"I had never imagined that my mobile phone was anything other than a safe and inviolate place where I could communicate with all of the people in my life. That feeling has been shattered."
Yentob was giving evidence on Friday at a hearing in London to decide the amount of compensation to be awarded in eight representative cases involving himself, actress Sadie Frost, ex-footballer Paul Gascoigne, soap stars Lucy Taggart, Shane Richie and Shobna Gulati, flight attendant Lauren Alcorn and TV producer Robert Ashworth.
His counsel, David Sherborne, has told Mr Justice Mann that phone-hacking was rife at all three of MGN's national titles by mid-1999 at the latest and that Yentob's voicemail was an "Aladdin's Cave" of stories because of his circle of high-profile friends – although no articles about him were published.
Between 1999 and 2008, tens of thousands of calls were made to Yentob's phone, which was left on most of the day with messages piling up.
Yentob said that, at this time, he would have been in regular contact with, among others, Lady Ruth Rogers and her architect husband Richard, the then BBC director-general Greg Dyke, actors Mel Brooks and Anne Bancroft, author Salman Rushdie, Alastair Campbell at Downing Street, entertainers Harry Enfield, Jonathan Ross, Steve Coogan, Angus Deayton and Caroline Aherne, and musician Sting and his wife Trudie Styler.
Yentob said Lady Rogers and her husband and family were very close friends of many years standing and he would speak to her at least every other day.
In July 2002, he was on holiday in Italy with his family and, as had happened for the previous 15 years, Lady Rogers and her family took the house next to them.
"The Rogers were not the only family with whom we spent the summer. We were also joined by other friends such as Charles Saatchi, Nigella Lawson and Alan Rusbridger, editor of The Guardian.
"The musician Sting and his wife Trudie Styler owned a house nearby, at which we would stay as guests."
He said MGN suspected he was having an affair with Lady Rogers, although at some point it realised that was not correct and so could not publish the story.
"That it was nonsense is true. But this in no way excuses the intrusion into our privacy. We never had an affair, but it does not mean that it would not have had devastating effects had the story been published.
"Upsetting not just for me, Ruth, Philippa (his partner) and Richard, but also for our children who were friendly with each other, and our wider family too."
Yentob said their families and long-term friendships would have been "irreparably damaged" by such a story, even though he trusted their respective partners would have known it was nonsense.
"However, those outside of the family, people I work with, friends and acquaintances may not have known the truth. They might easily have thought there was no smoke without fire, given that it appeared in the newspaper."
Yentob, who said he genuinely believed in a "free and vibrant" press, said the journalists would have been privy to matters to do with his health, domestic issues, financial or business dealings, and commercially-sensitive information about the BBC.
He said he now knew that at least 16 journalists were involved in hacking his phone, and he felt very let down that such unlawful activity was "endemic and part of a culture of profound dishonesty".
The events did not feel historic to him: "I still feel this was a horrific invasion of my personal and professional life."
Earlier, Matthew Nicklin QC, for MGN, which had admitted liability in September last year, repeated the group's public apology for the harm that had been caused and its intention to pay "full, fair and proper" compensation to the claimants.
"These unlawful activities have long been banished from Trinity Mirror's business, but Trinity Mirror is facing up to and taking responsibility for this historic wrongdoing."
He said that, contrary to the suggestion that there had been a cover-up, the significant co-operation by Trinity Mirror had been acknowledged and welcomed on a regular basis by the Metropolitan Police since the start of the long and complex inquiry.
Nicklin said that no evidence would be produced during the trial to show that the board of Trinity Mirror was aware that hacking was going on at the time of the Leveson inquiry or that MGN denied the first four claims of phone-hacking, knowing that its denial was false.
There was also no evidence that there was any kind of cover-up or that a large number of journalists – a "horde" as the claimants put it – were involved in hacking.
"On this last point, it is quite wrong, unfair and unjust, to taint a large number of honest, hard-working journalists with the wrongdoing of a few. The evidence upon which this is sought to be done is paper-thin."
The hearing was adjourned to today.