Prince Harry said he was determined to take the publisher of the Mail newspapers to task as he said he was “deeply concerned” by their “unbridled power, influence and criminality”.
His witness statement was disclosed as part of his privacy lawsuit against Associated Newspapers.
In it, he also said that he did not join the Royal Family’s discussions about taking legal action over phone hacking.
He attended the High Court for the second day of legal arguments on Tuesday.
The Duke of Sussex and six other claimants, including Sir Elton John and Baroness Doreen Lawrence – the mother of murdered teenager Stephen Lawrence – say their personal information was illegally obtained and used as material for the Daily Mail and Mail on Sunday stories.
Associated Newspapers dismissed the claims as “preposterous smears” based on a “fishing expedition”.
In the duke’s statement, he criticized the publisher’s attempts in court this week to have the case thrown out on legal grounds.
“Unfair is not a big enough word to describe the fact that Associated is trying at this early stage to prevent me from bringing my claim,” the statement said.
“If the UK’s most influential and popular newspaper can escape justice without a trial over my claims, then what does that say about the industry as a whole and the consequences for our great country.
“I am bringing this claim because I love my country and I remain deeply concerned about the unchecked power, influence and criminality of the Associated.”
The statement details the stories the duke claims are based on private information that was illegally obtained.
They included reports about his relationships with two girlfriends.
He also criticized a story about his reaction, along with his brother William, to the publication of photos of his dying mother in the Italian media.
“It’s absolutely disgusting,” he said, with a “crude headline” and “blatant reference to a phone call”.
“My brother and I were quite young at the time (I was only 21) and we were having a private conversation about pictures of our dead mother being put in the public domain.”
In his witness statement, Prince Harry said the Royal Family – which he referred to as the Institution – withheld information from him about the possibility of taking legal action in response to media intrusions.
She said she only started talking to a senior lawyer for the Royal Family when she started dating her now-wife and “damaging stories” were published.
The prince eventually learned he could take legal action over phone hacking in 2018, he said.
“The Institution has made it clear that we don’t need to know anything about phone hacking and made it clear to me that the Royal Family will not sit in the witness box because that could open a can of worms,” he said.
Meanwhile, fellow claimant Sir Elton John has accused a private investigator of tapping his home phone and that of his gardener.
He said it was a “violation of our home and the safety of our children and loved ones.”
Sir Elton is seeking damages in relation to 10 articles in which he says the Mail titles “misappropriated information they stole from our family and friends”.
In his witness statement, he said the Mail took advantage of “love, connection, trust and bonds to find out information shared in confidence”.
Sir Elton’s case against Associated Newspapers included claims that a private investigator had obtained details of his medical conditions, including that he “fell in a plane”.
Her husband, David Furnish, is also pursuing High Court legal action.
His statement revealed that the couple had been informed by actor Liz Hurley about the allegation that their live phone calls had been intercepted by an investigator working for the Mail on Sunday.
He said the investigator appeared to know that Sir Elton did not have his own mobile phone and used several landlines.
Ms Hurley said her calls were also tapped.
Baroness Lawrence said private investigators working for the Daily Mail tapped her home phone and hacked her voicemails.
In his own statement to the High Court, he also accused the newspaper of commissioning investigators to monitor his bank accounts and phone bills.
He said he trusted the Daily Mail, which campaigned hard for justice for his family, but concluded: “I’ve been played for a fool.”
Associated Newspapers dismissed his allegations as “horrendous and completely unfounded smears”.
The publisher said the claims were based on the word of private investigator Jonathan Rees, who served a prison sentence for perverting the course of justice.
In a statement last year, Associated said: “It is deeply regrettable that whoever cynically and unscrupulously orchestrated these claims appears to have encouraged Baroness Lawrence – for whom the Mail has the greatest respect and admiration – to endorse the word of such a person. an openly discredited and untrustworthy liar.”
But Baroness Lawrence said in her witness statement, which was released to the court, that she feared the actions of private investigators could interfere with investigations into Stephen’s murder.
In his statement, he said: “We had a good relationship with the press and in February 1997, we aligned ourselves with the Daily Mail and have always sought to be the guardians of truth and justice, those who fight against corruption and holding the bad guys accountable and really cares about the fact that the killers of my son go free.”
But when the alleged use of private investigators was discovered, he said there was a “level of trust” and “the betrayal I felt when that was taken away and I realized it was all wrong was intense.”
He added: “I can’t think of any action or behavior less than stealing and exploiting information from a murder and from a mother who buried her child, and by people who pretended to be my friends.
“This is a new trauma and injustice for me.”
Allegations in the lawsuit against Associated Newspapers include phone tapping, “hacking” of voicemail messages and the use of private investigators to obtain personal data.
More than 70 journalists have been implicated in the allegations made by seven claimants – Prince Harry, Sir Elton John and his wife David Furnish, Sadie Frost, Liz Hurley, Baroness Doreen Lawrence and Sir Simon Hughes.
Their names cannot be reported for legal reasons.
Tuesday’s legal arguments centered on ledgers setting out payments made by Associated Newspapers (ANL) to 19 private investigators in the past, allegedly working for journalists.
The seven claimants said they were for large sums of money and this was proof that illegal methods were being used to gather information about them.
The ledgers were revealed at the Leveson Inquiry into journalism standards in 2011.
ANL is trying to drop part of the case because, it says, the Leveson files cannot be used in other cases, due to confidentiality rules.
The company also says that two barristers in the case, and Sir Simon Hughes, were closely involved in the Leveson Inquiry and gave “undertakings” not to disclose the documents they received.
Barristers for ANL told the court that these restrictions must be lifted by the government if the evidence is to be used in the current case. This did not happen and they said that sections of the case that relied on ledgers should be deleted.
But David Sherborne, representing the seven Associated plaintiffs, told the judge, Mr Justice Nicklin, that the ledgers had in fact been obtained by an investigative journalist, not from the Leveson Inquiry.
As a leading barrister at the Leveson Inquiry, representing victims of press interference, he personally agreed not to disclose confidential information.
But he said the practice ended when the inquiry report was published in 2012.
The court also released the witness statement of private investigator Gavin Burrows, who denied all allegations that he hacked phones, tapped landlines, or bugged cars on behalf of the Daily Mail or Mail on Sunday.
Responding to specific allegations made by Prince Harry, Baroness Lawrence, Elton John, David Furnish, Sadie Frost and Liz Hurley, he said: “I was not ordered or instructed by the Mail on Sunday or the Daily Mail to do anything in breach of information gathering law.”
Two other private investigators also made statements in court admitting their role in providing illegally obtained information to journalists at the Daily Mail and Mail on Sunday.