The Duke of Sussex will discover the outcome of his unlawful information gathering claim against a tabloid newspaper publisher in a High Court ruling on Friday.

Harry, 39, sued Mirror Group Newspapers (MGN) for damages, claiming journalists at its titles – the Daily and Sunday Mirror and Sunday People – were linked to methods including phone hacking, so-called “blagging” or gaining information by deception, and use of private investigators for unlawful activities.

His case was heard alongside similar claims brought by actor Michael Turner, who is known professionally as Michael Le Vell and is most famous for playing Kevin Webster in Coronation Street, actress Nikki Sanderson and comedian Paul Whitehouse’s ex-wife, Fiona Wightman.

The allegations in their claims about unlawful activity at MGN’s titles cover a period from as early as 1991 until at least 2011, the court was told.

Mr Justice Fancourt, the judge who oversaw a trial of the claims earlier this year, is expected to give his ruling at a hearing on Friday.

The high-profile trial ended in June after seven weeks of evidence from dozens of witnesses, including former journalists, editors, private investigators and MGN executives.

Many other witnesses also submitted written testimony to the trial, such as the friends, family and colleagues of those bringing cases against the publisher.

Harry faced eight hours of questioning over two days during a witness box appearance that drew the attention of the world’s media.

MGN largely contested the claims and denied that any newspaper articles complained of resulted from phone hacking, while contending that the vast majority did not arise from any other unlawful activity.

The publisher made a limited number of admissions of unlawful activity in relation to the duke, Ms Sanderson and Ms Wightman, for which the publisher apologised and accepted they will be entitled to some damages, but denied the majority of their claims and Mr Turner’s entire case.

The hearing in London is set to begin at 10.30am.