Prince Harry in London for privacy lawsuits against publisher of British tabloid Daily Mail

Prince Harry made a surprise appearance Monday morning at the High Court in London where a hearing is being held against the publisher of the Daily Mail, Associated Newspaper [ANL], accused by several celebrities of illegally gathering information.

The hearing involves one of several lawsuits the Duke of Sussex has brought against the media. It is expected to last for four days.

In the legal proceedings in London, the six plaintiffs accuse ANL of employing detectives to wiretap them, in their cars or at their homes.

“They were the victim of numerous unlawful acts carried out by the defendant, or by those acting on the instructions of its newspapers, The Daily Mail and The Mail On Sunday,” attorney David Sherborne said.

The allegations date back to 1993 and continue beyond 2018, Sherborne said.

The publisher has denied the accusation. In October, it refuted "totally and unambiguously these preposterous smears which appear to be nothing more than a planned and orchestrated attempt to drag the Mail's headlines into the wiretapping scandal concerning 30-year-old articles."

The publisher said the claims are too old to be brought now and should also be thrown out because they rely on information the newspapers turned over in confidentiality for a 2012 probe into media law-breaking.

Britain held a year-long inquiry into press ethics after revelations in 2011 that News of the World tabloid employees eavesdropped on the mobile phone voicemails of celebrities, politicians and a teenage murder victim.

More than 60 journalists were arrested in the wake of the scandal.