The owner of the Sun has been ordered to hand over thousands of invoices relating to the use of private investigators by the newspaper and its former sister title, the News of the World, before a new hacking trial later this year.

Mr Justice Mann made a judgment on Tuesday that News Group, part of Rupert Murdoch’s News Corp, must disclose invoices from between 2000 and 2010 for the use of private investigators that have been found to have connections with phone hacking and unlawfully obtaining personal information. This means News Group will hand over more than 6,000 invoices on its database.

The judge also said that News Group must explain why it has made redactions on hundreds of documents relevant to the hacking case and that laptops used by James Murdoch, the former chairman of News International, should be searched for potentially relevant documents.

The judgments came after lawyers representing alleged victims of phone hacking told the judge that News Group has “consistently failed to provide proper disclosure and to meet its disclosure obligations”. This was denied by the company. The claimants have already alleged that senior executives at News Group were involved in authorising the deletion of emails after the hacking scandal escalated in 2010 and want access to more emails written by Rebekah Brooks, the chief executive of News Corp’s UK business, James Murdoch, and other senior staff.

The judgments were issued at case management hearing at the high court in London ahead of a trial in October. A collection of 91 individuals have alleged that personal information about them was obtained illegally by News Group, including through phone hacking. Sir Elton John, Gordon Ramsay and David Tennant are among the alleged victims.

News Group has already settled with more than 1,000 people about hacking, but this was related to the News of the World, which was closed in 2011 at the height of the hacking scandal. The company has denied that widespread hacking took place at the Sun.

Before the hearing News Group had released 816 invoices that were determined as relevant to the claimants’ case. It also released 1,236 invoices covering two six-month periods in 2002 and 2005. These samples were released after the company was told at an earlier hearing to release all invoices from private investigators linked to phone hacking from two sample periods over the last 10 years, so the claimants could consider whether the disclosure of the relevant documents was fair.

David Sherborne, acting for the claimaints, said that the number of documents in the samples and the fact some of them also appeared relevant to the case showed it was “inexplicable” that News Group had not released more invoices. He added: “It is quite clear the defendant has not disclosed invoices they should have disclosed.”

Anthony Hudson, representing News Group, said the claimants were “focusing inappropriately and massively disproportionately on invoices that go nowhere”. Hudson told the judge that “enough is enough” in terms of the disclosure requests by the claimants, referring to the “enormous disclosure exercise” that the company has undertaken. In legal documents, News Group added: “Having reached that point, it is evident that the disclosure simply does not bear out the claimants’ allegations of widespread voicemail interception at the Sun, whether in relation to particular claimants or generally.”

Mann said there was “unfortunate history to this part of the case” because last year News Group had said it did not have any relevant private investigator invoices. He said there was there was no allegation of improper behaviour by News Group and lawyers at Clifford Chance had reviewed the invoices and determined which were relevant. However, he said all invoices relating to the use of private investigators between 2000 and 2010 must be provided by 28 June.

The judge also said that News Group must explain the redactions on around 800 documents within 21 days. The company said the redactions were due to protecting sources and legal privilege, but the claimants disputed this. Mann told News Group: “The clock is definitely striking 13 on this.”

The claimants want James Murdoch’s laptops to be included in the case “to ensure that all of Mr Murdoch’s potentially relevant documents are searched”. Murdoch is already an agreed custodian in the case, meaning that both parties agree his electronic documents could be relevant in the case. Lawyers for News Group said it was “far too late” to make new requests about searching documents and that it had already compiled an extensive pool of data from the company and those who work for it.