Princess Diana’s former lover James Hewitt and her butler Paul Burrell are among dozens of individuals who have joined Prince Harry in the latest round of phone-hacking claims against tabloid newspaper publishers.

Hewitt and Burrell recently filed their cases against the publisher of the Daily Mirror at the high court, according to court filings seen by the Guardian, joining the Duke of Sussex in alleging the publisher intercepted their voicemails. Their claims will focus attention on the extent to which British newspapers targeted the royal family and those around them in the hunt for stories during the 2000s.

The current round of phone-hacking claims has received substantially more attention since Prince Harry launched proceedings against the publishers of both the Mirror and the Sun last month, as part of the all-out-war on tabloid media intrusion that he is fighting with his wife Meghan, Duchess of Sussex.

Meanwhile, the family of the late Newcastle United manager and cancer fundraiser Sir Bobby Robson have separately launched legal action against the publisher of the Sun for alleged interception of his voicemails. His family declined to comment on the decision to start legal action in the name of the former England manager, who died in 2009 before the full scale of the phone-hacking scandal became apparent. Robson has not previously been named as a potential victim of illegal press intrusion.

Other individuals who have recently filed proceedings against the News Group Newspapers – the publisher of the Sun and the defunct News of the World – for alleged misuse of private information include the singer Cheryl Tweedy, the former Liberal Democrat MP Sir Simon Hughes, and the actor Sienna Miller.

Facebook Twitter Pinterest Sir Bobby Robson has been named as a potential victim of illegal press intrusion for the first time. Photograph: Ian Hodgson/REUTERS

Many of the allegations are thought to relate to articles which ran in newspapers during the mid-2000s, with solicitors continuing to bring new cases which are dealt with by the courts on a collective basis. The deadline for potential victims to join the current round ends in November, with any trial unlikely to happen before next October.

Hughes and Miller’s claims against the publisher are notable because they have both already successfully sued the publisher for phone hacking at the News of the World, suggesting they may have further claims against the company’s news outlets.

The new round of cases, most of which are thought to include allegations of voicemail interception in the 2000s, are proving to be a costly drain on the resources of tabloid newspapers at a time when the news outlets are also dealing with plummeting circulations and falling revenue.

Mirror Group Newspapers is also facing claims for alleged misuse of private information from the singer Lily Allen, the model Daisy Lowe, the footballer Stan Collymore, the reality show star Dani Behr, and Eunice Huthart – better known as “Blaze” on Gladiators.

Some of the names of those bringing the cases were first reported by the website Byline Investigates.

Facebook Twitter Pinterest The actor Sienna Miller also recently filed proceedings against the News Group Newspapers, the publisher of the Sun and the defunct News of the World Photograph: Lucas Jackson/Reuters

Despite claims in open court that Sun reporters have been involved in phone hacking, News Group Newspapers has always said that all wrongdoing was limited to the closed-down News of the World. The company’s settlements with phone-hacking victims have been accompanied by statements making clear that reporters at the defunct Sunday newspaper were entirely responsible for the illegal voicemail interception.

Other individuals who have started proceedings against the publisher of the Sun in recent weeks include the reality TV contestant Imogen Thomas in addition to the soap actors Gary Lucy, Michelle Collins, and Richard Fleeshman. They are joined by Rebecca Loos, who hit the headlines in 2004 for her relationship with footballer David Beckham and her subsequent exploration of agricultural issues on the Channel 5 reality show The Farm.