Doreen Lawrence has claimed the Daily Mail hired private investigators to hack her phone and obtain information on her murdered son, potentially disrupting the police investigation into the racially motivated killing. Lady Lawrence now believes she “failed her murdered son” by trusting the Daily Mail during the 1990s, claiming the news outlet only campaigned for justice on behalf of Stephen Lawrence in a cynical bid to sell more newspapers. The allegations were set out in detailed documents released during an extraordinary hearing at the high court. Lawrence, the Duke of Sussex and Elton John all turned up to hear legal arguments in the cases they have brought against Associated Newspapers, the owner of the Daily Mail, the Mail on Sunday and MailOnline. Along with actors Sadie Frost and Liz Hurley, and the former Liberal Democrat politician Sir Simon Hughes, they accuse the titles of making widespread use of illegal reporting tactics to obtain stories over more than 20 years. At Monday’s preliminary hearing in central London, lawyers for Associated Newspapers attempted to stop the claims from going to trial, where the allegations would be heard in full. At the end of proceedings Harry – who had sat at the back of the court making notes – headed straight to warmly greet Lawrence, engaging the Labour peer in conversation and chatting as they headed out of the courtroom together. Until now the Daily Mail has largely escaped the phone-hacking allegations that led to the closure of the News of the World but the newspaper now faces a major challenge that could result in serious reputational damage. The allegations relate to a period when the Daily Mail was edited by Paul Dacre, who remains a senior executive at Associated Newspapers and has been nominated for a peerage in Boris Johnson’s resignation honours. The Mail has dismissed all the claims as “preposterous smears” and is trying to stop the case going to trial on multiple grounds. The newspaper ran a long campaign to identify the racist killers of Stephen Lawrence, culminating in a front-page story accusing five individuals of murder. The paper often held up the story as an example of newspaper’s commitment to fighting for justice on behalf of those who lack a voice, recently calling its campaign a “key moment in British race relations history”. Lawrence said she now believed the campaign on behalf of her son was a cynical way to sell newspapers by appearing to be on the side of a young man killed in a racist attack. In documents filed to court, her lawyers said Lawrence “cannot think of any act or conduct lower than stealing and exploiting information from a mother who buried her son for this reason”. “She feels used and violated, and like she has been taken for a fool.” Rather than campaigning due to a genuine desire to get justice for Stephen, she “now sees that the Daily Mail’s true interests were about self-promotion and using her and her son’s murder as a means to generate ‘exclusive’ headlines, sell newspapers, and to profit”. “She wonders whether trusting the Daily Mail as she did caused her to have delayed or have failed her murdered son,” the documents say. “She asks herself whether more individuals could have been arrested, whether earlier investigations might have been more successful, and whether she could have got justice.” The documents say Lawrence now “feels a deep sense of betrayal. She finds it hard to believe the level of duplicity and manipulation that was clearly at play, knowing now as she does that the Daily Mail’s outward support for her fight to bring Stephen’s killers to justice was hollow, and worse, entirely false”. Among other claims, she alleges the Daily Mail instructed private investigators to: conduct illegal interception of her voicemail messages, tap her landline telephone, blag personal records, monitor her bank accounts and phone bills, conduct covert electronic surveillance and make corrupt payments to serving Metropolitan police officers working on her son’s murder investigations in return for confidential information. She said that to this day the Mail continued to engage in “manipulation and pretence of being on her side”. The Daily Mail strongly denies the allegations and said that they believe Lawrence has been “persuaded to bring this case”. Lawyers for Associated Newspapers are seeking to stop the cases progressing to court – while also restricting the ability of the rest of the media to report on the allegations. In all, there are seven claims against Associated Newspapers. In the court documents, Prince Harry said he had been targeted for information about his private relationship and alleged the unlawful activity used to obtain these stories meant “he was largely deprived of important aspects of his teenage years”. He said friends were lost or cut off as a result and everyone became a “suspect”, arguing that the stories were written in a manner that led him to believe those close to him were the source of the information being provided to the Daily Mail and Mail on Sunday. Elton John and his husband, David Furnish, allege the landline telephone at their home was illegally tapped by investigators working for the Mail’s parent company. On Monday Associated successfully invoked the Human Rights Act to stop other media outlets identifying 73 of its journalists who are named in the court proceedings. Its lawyers said publishing the names would breach the journalists’ right to a fair trial under the Human Rights Act. David Sherborne KC, representing Harry and other claimants at the high court, noted it was surprising to see a newspaper that has campaigned for press freedom object to the publication of the names. “They say different rules apply to their journalists suspected of wrongdoing, as opposed to others suspected of wrongdoing.” Associated Newspapers is attempting to stop the cases going to trial on two separate grounds. First, it alleges that the claims are “stale” because the seven individuals waited too long to file their legal paperwork – essentially arguing that the individuals must have had reasonable suspicion that they were potential victims more than six years ago. Second, its lawyers claim that key parts of the evidence come from confidential material submitted to the 2011 Leveson inquiry into the culture of the British media. They say this was then obtained by an unknown individual from the inquiry’s internal systems, breaching the terms on which the information was provided. While most of the claims that British courts have dealt with at the Sun, News of the World, and Mirror focus on voicemail interception – also known as phone hacking – the allegations against the Mail group go much further and rely on the supposed work of private investigators. Among the allegations against the Mail’s parent company are that individuals working for its newspapers illegally intercepted voicemail messages, listened into live landline calls, obtained medical records by deception or “blagging”, and even commissioned the breaking and entry into private property. An Associated Newspapers spokesperson said a “private investigator whose ‘confessions’ form a key element” of the case has since provided a sworn statement that he was not “commissioned or instructed” to carry out any illegal work for either Mail title. They added that while the “Mail’s admiration for Baroness Lawrence remains undimmed, we are profoundly saddened that she has been persuaded to bring this case … The Mail remains hugely proud of its pivotal role in campaigning for justice for Stephen Lawrence. Its famous ‘Murderers’ front page triggered the Macpherson report”. The spokesperson said: “Associated Newspapers, which owns the Daily Mail and Mail on Sunday, vigorously denies all the claims against it.”