“Extensive” phone hacking took place at Mirror Group Newspapers (MGN) titles over multiple years, a High Court judge has ruled, after a trial involving the Duke of Sussex.

In a 386-page ruling on Friday, Mr Justice Fancourt made a number of findings about the extent of unlawful information gathering at the Daily and Sunday Mirror and The People.

As well as phone hacking, this also included so-called “blagging” or gaining information by deception, and use of private investigators for unlawful activities.

The ruling came after a seven-week trial featuring a “generic” case about activities at MGN, as well as cases brought by four “representative” claimants, including Harry.

Here the PA news agency looks at the key findings in the landmark judgment.

– Phone hacking

After a seven-week trial earlier this year, the High Court judge found that unlawful information-gathering was “widespread” at all three Mirror Group titles from 1996 onwards, and phone hacking became “habitual” from 1998.

Mr Justice Fancourt said there was “extensive” phone hacking generally by MGN from 2006 to 2011, “even to some extent” during the Leveson Inquiry into media standards.

He said it was “done in a more controlled way” after August 2006, “but it remained extensive throughout”.

The judge also found “it was, with very few exceptions, carried out by the editors or journalists” rather than by private investigators.

A previous High Court judgment in 2015 found there was unlawful information gathering by MGN between 1999 and 2006.

Friday’s judgment now extends the total period of unlawful information gathering found proven by a judge from 1995 to 2011.

– Private investigators

The senior judge found 11 private investigators were used ”very substantially” by journalists and editors at MGN in connection with unlawful information gathering.

A further 13 investigators did a “significant amount” of unlawful information-gathering work for the publisher, Mr Justice Fancourt said.

The court heard this included “blagging confidential information” from third parties including banks, hospitals and telephone companies, as well as voicemail interception.

Other methods included unlawful searches, including illicit credit reference checks, for information that could be used for further stories.

“The critical thing for MGN was to obtain information that was either newsworthy in its own right, such as the location of a celebrity and who they were with, or which provided the opportunity to conduct its widespread and habitual phone-hacking activities, which would then provide the newsworthy information,” Mr Justice Fancourt ruled.

The judge largely dismissed allegations related to the use of 14 private investigators and found there were 10 further people who were based abroad and no case had been proved that what they were doing abroad was unlawful.

He also found that searches using Companies House and the Land Registry were “likely to have been legal searches of public registers”.

– Concealment

Mr Justice Fancourt said “there can be no doubt” that the editors of the newspapers knew about voicemail interception and other unlawful information gathering.

The judge said the unlawful activity was “concealed” from Parliament, shareholders and the public, as well as the board overseeing MGN.

In his summary of the ruling, Mr Justice Fancourt said: “The board as a whole was not told about it.

“That was because the editors of the three newspapers, the editorial managers of the company and [chief executive Sly] Bailey and [group legal director Paul] Vickers did not report what they knew, or suspected, to the board.

“The likelihood of extensive illegal activity should have been investigated properly by Ms Bailey and Mr Vickers, at the latest in early 2007, but it never was.

“Instead, it was concealed from the board, from Parliament in 2007 and 2011, from the Leveson Inquiry, from shareholders and from the public for years, and the extent of it was concealed from claimants in the Mirror Newspapers hacking litigation and even from the court at and before the trial in 2015.”

The judge added that the company’s in-house lawyers also knew about the use of phone hacking due to their involvement in checking articles for publication.

Mr Justice Fancourt said in his judgment: “Even today, MGN is not being open about the extent to which VMI [voice mail interception] and UIG [unlawful information gathering] went on at its newspapers.”

– Duke of Sussex

The judge found that it was “implausible that serial phone hackers at MGN’s newspapers, who were using these techniques on a widespread and habitual basis, would have considered members of the royal family off-limits” and that Harry was probably hacked “to a modest extent”.

Mr Justice Fancourt continued: “All three newspapers, and other tabloids, were obsessed with stories about the royal family and about Prince Harry in particular, which doubtless reflected the apparent public appetite for information about his successes and failures, his career, and in particular his love life.”

The judge found that the phone hacking of the duke personally began in late 2003 “at the earliest” and was then performed in a “targeted and controlled way”.

“So far as the duke personally was concerned, his phone was probably targeted on occasions when there was an important storyline that MGN journalists were chasing, such as the ups and downs of the duke’s relationship with [Chelsy] Davy,” he ruled.

Mr Justice Fancourt said that 15 of the 33 articles about Harry examined at trial “were the product of phone hacking of his mobile phone or the mobile phones of his associates, or the product of other unlawful information-gathering”.

Both sides of the case selected articles to be used at the trial, out of a total of 148 articles in the duke’s claim.

The judge said he was awarding damages totalling £140,600 to the duke where unlawful information-gathering was proved, and also to compensate him “fully for the distress that he suffered as a result of the unlawful activity directed at him and those close to him”.

However, he added: “On any view, the duke’s misery caused by press behaviour, which MGN acknowledged, was not the fault of MGN alone, and I can only properly award damages against MGN for its contribution to the consequences of unlawful activity, not general hounding of the duke by the press that does not involve any unlawful information gathering.”

– Other claimants

Actor Michael Turner, known professionally as Michael Le Vell, was awarded a total of £31,650 in damages after he also brought a phone-hacking claim against the publisher.

The judge said: “I have found Mr Turner’s case of voicemail interception and unlawful information-gathering proved only to a limited extent, and mainly only in respect of the period in 2011 when he was the subject of prosecution in the Crown Court, and so was of particular interest to the press at that time.

“Mr Turner brought a claim in respect of 27 articles, some of which were exceedingly trivial and others were, on sensible reflection, obviously not the result of unlawful information-gathering.”

However actress Nikki Sanderson and Fiona Wightman, the ex-wife of comedian Paul Whitehouse, both had their claims dismissed because they were made too late.

“The result can, and probably will, be said to be harsh in Ms Wightman’s case and it is not a conclusion that I reach with any pleasure,” Mr Justice Fancourt said.

The judge ruled that if the claims had been brought in the correct timeframe, Ms Sanderson would have been awarded £67,500 in damages and Ms Wightman would have been granted £22,750.