Lawyers for Ian Baileys say they have received 12 boxes of documents and 130 tapes of recorded conversations revealing an "extraordinary" level of communication between gardaí and the media.
The former journalist is suing the garda authorities for damages over their investigation into the murder of French film-maker Sophie Toscan du Plantier in 1996.
Today his lawyers informed the High Court that as part of the pre-trial disclosure process they have recently received 12 boxes of documents and 130 tapes of phone recordings.
All the material is entirely new, Mr Bailey's legal team said.
While they have not yet had a chance to process the information, Mr Bailey's lawyers say it is of huge relevance and discloses an extraordinary level of communication between the gardaí and media in relation to Mr Bailey's case.
Barrister Martin Giblin referred to a list of "hundreds and hundreds" of communications with journalists.
Disclosure is still ongoing but the case is set to go before a High Court jury this October.
Mr Bailey's legal action was the first to set alarm bells ringing last November about the taping of phone conversations at garda stations.