Prince Harry addresses James Hewitt rumors during testimony in tabloid court case

Prince Harry took to the witness stand in a U.K. courtroom on Tuesday, becoming the first British royal to do so in more than a century.

The Duke of Sussex was grilled by the defense team in his lawsuit against Mirror Group Newspapers, the publisher of The Daily Mirror.

Harry and 100 other celebrities, including the estate of the late George Michael, are suing Mirror Group Newspapers for alleged misuse of private information between 1991 and 2011, including phone hacking and intercepting voicemails.

In a prepared witness statement released Tuesday, Harry said the articles published about himself and his family played a destructive role in his childhood and provoked feelings of paranoia in him.

"As a teenager and in my early 20s, I ended up feeling as though I was playing up to a lot of the headlines and stereotypes that [the tabloid press] wanted to pin on me mainly because I thought that, if they are printing this rubbish about me and people were believing it, I may as well 'do the crime,' so to speak," Harry said in the statement. "It was a downward spiral, whereby the tabloids would constantly try and coax me, a 'damaged' young man, into doing something stupid that would make a good story and sell lots of newspapers."

He continued, "Looking back on it now, such behavior on their part is utterly vile."

Harry, the youngest child of King Charles III and the late Princess Diana, also addressed the tabloid rumors that he was born from an affair between Diana and James Hewitt.

Harry said in his witness statement that he wondered if the rumors were planted by the tabloids so that he would be "ousted from the Royal Family."

"Numerous newspapers had reported a rumour that my biological father was James Hewitt, a man my mother had a relationship with after I was born. At the time of this article and others similar to it, I wasn't actually aware that my mother hadn't met Major Hewitt until after I was born," Harry said in his statement. "This timeline is something I only learnt of ... around 2014, although I now understand this was common knowledge amongst the Defendant's journalists."

He continued, "At the time, when I was 18 years old and had lost my mother just six years earlier, stories such as this felt very damaging and very real to me. They were hurtful, mean and cruel. I was always left questioning the motives behind the stories. Were the newspapers keen to put doubt into the minds of the public so I might be ousted from the Royal Family?"

Harry's legal team has accused Mirror Group Newspapers of unlawfully gathering information on an "industrial scale."

"It was a flood of illegality," Harry's attorney, David Sherborne, said in his opening statement in the trial last month, according to The Associated Press. "But worse, this flood was being approved by senior executives, managing editors and members of the board."

Mirror Group Newspapers is contesting the claims, saying in the 33 articles being examined by the court that its reporters found the information through lawful reporting.

The publisher did apologize after noting that in other instances, "some evidence of the instruction of third parties to engage in other types of UIG (unlawful information gathering)," according to the AP.

"MGN unreservedly apologizes for all such instances of UIG, and assures the claimants that such conduct will never be repeated," the publisher said in court papers.

Harry's testimony in the case is expected to continue on Wednesday.

The prince traveled to the U.K. just prior to his testimony Tuesday because of a late flight to the U.K. after celebrating the birthday of his daughter, Lilibet, who turned 2 on Sunday, according to his attorney.

Harry and his wife Meghan, the Duchess of Sussex, live in California with Lilibet and their 4-year-old son, Archie.

Since stepping down from his role as a senior working royal in 2020, Harry has made no secret of his disdain for the British tabloid media. In his witness statement, Harry said it he has "a very difficult relationship with the tabloid press in the U.K."

"Harry is somebody that is very clear in what he wants to achieve. He believes he has been treated badly by this newspaper group," said ABC News royal contributor Robert Jobson. "He believes he's had his phone hacked by this newspaper group and therefore is determined, as he is right, to be compensated for it, and to receive an apology."

The lawsuit against the Mirror Group Newspapers is one of six lawsuits that Harry is currently waging against the British tabloids.

He made an unexpected appearance in a U.K. courtroom in March for a hearing on a lawsuit that he, Elton John and other celebrities have brought against Associated Newspapers Ltd., the publisher of the Daily Mail, The Mail on Sunday and the MailOnline.

The case, first announced last year, alleges the celebrity defendants are "the victims of abhorrent criminal activity and gross breaches of privacy," according to a press release shared last year by Hamlins, the London-based law firm representing Harry in the case.

Harry told ABC News' Michael Strahan in January that the lawsuits he is involved in are his attempt to bring about real change when it comes to the media coverage of celebrities and the royal family.

"I'm in this to be able to say, 'Draw a line. Enough. We can all move on and get on with our lives,'" he said. "But if this continues, then I'm naturally, deeply concerned that what has happened to us will happen to someone else."